Network Working Group J. Jeong, Ed. Internet-Draft P. Lingga Intended status: Standards Track Sungkyunkwan University Expires: 19 August 2022 S. Hares L. Xia Huawei H. Birkholz Fraunhofer SIT 15 February 2022 I2NSF NSF Monitoring Interface YANG Data Model draft-ietf-i2nsf-nsf-monitoring-data-model-15 Abstract This document proposes an information model and the corresponding YANG data model of an interface for monitoring Network Security Functions (NSFs) in the Interface to Network Security Functions (I2NSF) framework. If the monitoring of NSFs is performed with the NSF monitoring interface in a standard way, it is possible to detect the indication of malicious activity, anomalous behavior, the potential sign of denial-of-service attacks, or system overload in a timely manner. This monitoring functionality is based on the monitoring information that is generated by NSFs. Thus, this document describes not only an information model for the NSF monitoring interface along with a YANG tree diagram, but also the corresponding YANG data model. Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 19 August 2022. Jeong, et al. Expires 19 August 2022 [Page 1] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 Copyright Notice Copyright (c) 2022 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Use Cases for NSF Monitoring Data . . . . . . . . . . . . . . 5 4. Classification of NSF Monitoring Data . . . . . . . . . . . . 5 4.1. Retention and Emission from NSFs . . . . . . . . . . . . 6 4.2. Notifications for Events and Records . . . . . . . . . . 7 4.3. Push and Pull for the retrieval of monitoring data from NSFs . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5. Basic Information Model for Monitoring Data . . . . . . . . . 9 6. Extended Information Model for Monitoring Data . . . . . . . 10 6.1. System Alarms . . . . . . . . . . . . . . . . . . . . . . 11 6.1.1. Memory Alarm . . . . . . . . . . . . . . . . . . . . 11 6.1.2. CPU Alarm . . . . . . . . . . . . . . . . . . . . . . 11 6.1.3. Disk Alarm . . . . . . . . . . . . . . . . . . . . . 12 6.1.4. Hardware Alarm . . . . . . . . . . . . . . . . . . . 12 6.1.5. Interface Alarm . . . . . . . . . . . . . . . . . . . 12 6.2. System Events . . . . . . . . . . . . . . . . . . . . . . 13 6.2.1. Access Violation . . . . . . . . . . . . . . . . . . 13 6.2.2. Configuration Change . . . . . . . . . . . . . . . . 14 6.2.3. Session Table Event . . . . . . . . . . . . . . . . . 15 6.2.4. Traffic Flows . . . . . . . . . . . . . . . . . . . . 15 6.3. NSF Events . . . . . . . . . . . . . . . . . . . . . . . 16 6.3.1. DDoS Detection . . . . . . . . . . . . . . . . . . . 16 6.3.2. Virus Event . . . . . . . . . . . . . . . . . . . . . 17 6.3.3. Intrusion Event . . . . . . . . . . . . . . . . . . . 18 6.3.4. Web Attack Event . . . . . . . . . . . . . . . . . . 19 6.3.5. VoIP/VoCN Event . . . . . . . . . . . . . . . . . . . 19 6.4. System Logs . . . . . . . . . . . . . . . . . . . . . . . 20 6.4.1. Access Log . . . . . . . . . . . . . . . . . . . . . 20 6.4.2. Resource Utilization Log . . . . . . . . . . . . . . 21 6.4.3. User Activity Log . . . . . . . . . . . . . . . . . . 22 6.5. NSF Logs . . . . . . . . . . . . . . . . . . . . . . . . 23 Jeong, et al. Expires 19 August 2022 [Page 2] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 6.5.1. Deep Packet Inspection Log . . . . . . . . . . . . . 23 6.6. System Counter . . . . . . . . . . . . . . . . . . . . . 23 6.6.1. Interface Counter . . . . . . . . . . . . . . . . . . 23 6.7. NSF Counters . . . . . . . . . . . . . . . . . . . . . . 25 6.7.1. Firewall Counter . . . . . . . . . . . . . . . . . . 25 6.7.2. Policy Hit Counter . . . . . . . . . . . . . . . . . 26 7. YANG Tree Structure of NSF Monitoring YANG Module . . . . . . 27 8. YANG Data Model of NSF Monitoring YANG Module . . . . . . . . 35 9. I2NSF Event Stream . . . . . . . . . . . . . . . . . . . . . 84 10. XML Examples for I2NSF NSF Monitoring . . . . . . . . . . . . 85 10.1. I2NSF System Detection Alarm . . . . . . . . . . . . . . 85 10.2. I2NSF Interface Counters . . . . . . . . . . . . . . . . 87 11. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 89 12. Security Considerations . . . . . . . . . . . . . . . . . . . 89 13. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 91 14. Contributors . . . . . . . . . . . . . . . . . . . . . . . . 91 15. References . . . . . . . . . . . . . . . . . . . . . . . . . 92 15.1. Normative References . . . . . . . . . . . . . . . . . . 92 15.2. Informative References . . . . . . . . . . . . . . . . . 96 Appendix A. Changes from draft-ietf-i2nsf-nsf-monitoring-data-model-14 . . . . . . 97 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 97 1. Introduction According to [RFC8329], the interface provided by a Network Security Function (NSF) (e.g., Firewall, IPS, or Anti-DDoS function) to enable the collection of monitoring information is referred to as an I2NSF Monitoring Interface. This interface enables the sharing of vital data from the NSFs (e.g., events, records, and counters) to the NSF data collector through a variety of mechanisms (e.g., queries and notifications). The monitoring of NSF plays an important role in an overall security framework, if it is done in a timely way. The monitoring information generated by an NSF can be a good, early indication of anomalous behavior or malicious activity, such as denial-of-service (DoS) attacks. This document defines an information model of an NSF monitoring interface that provides visibility into an NSF for the NSF data collector. Note that an NSF data collector is defined as an entity to collect NSF monitoring data from an NSF, such as Security Controller. It specifies the information and illustrates the methods that enable an NSF to provide the information required in order to be monitored in a scalable and efficient way via the NSF Monitoring Interface. The information model for the NSF monitoring interface presented in this document is complementary for the security policy provisioning functionality of the NSF-Facing Interface specified in [I-D.ietf-i2nsf-nsf-facing-interface-dm]. Jeong, et al. Expires 19 August 2022 [Page 3] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 This document also defines a YANG [RFC7950] data model for the NSF monitoring interface, which is derived from the information model for the NSF monitoring interface. Note that this document covers a subset of monitoring data for systems and NSFs, which are related to security. 2. Terminology The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. This document uses the terminology described in [RFC8329]. In addition, the following terms are defined in this document: * I2NSF User: An entity that delivers a high-level security policy to the Security Controller and may request monitoring information via the NSF data collector. * Monitoring Information: Relevant data that can be processed to know the status and performance of the network and the NSF. The monitoring information in an I2NSF environment consists of I2NSF Events, I2NSF Records, and I2NSF Counters (see Section 4.1 for the detailed definition). This information is to be delivered to the NSF data collector. * Notification: Unsolicited transmission of monitoring information. * NSF Data Collector: An entity that collects NSF monitoring information from NSFs, such as Security Controllers. * Subscription: An agreement initialized by the NSF data collector to receive monitoring information from an NSF. The method to subscribe follows the method explained in [RFC5277]. This document follows the guidelines of [RFC8407], uses the common YANG types defined in [RFC6991], and adopts the Network Management Datastore Architecture (NMDA) [RFC8342]. The meaning of the symbols in tree diagrams is defined in [RFC8340]. Jeong, et al. Expires 19 August 2022 [Page 4] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 3. Use Cases for NSF Monitoring Data As mentioned earlier, monitoring plays a critical role in an overall security framework. The monitoring of the NSF provides very valuable information to an NSF data collector (e.g., Security Controller) in maintaining the provisioned security posture. Besides this, there are various other reasons to monitor the NSF as listed below: * The I2NSF User that is the security administrator can configure a policy that is triggered on a specific event occurring in the NSF or the network [RFC8329] [I-D.ietf-i2nsf-consumer-facing-interface-dm]. If an NSF data collector detects the specified event, it configures additional security functions as defined by policies. * The events triggered by an NSF as a result of security policy violation can be used by Security Information and Event Management (SIEM) to detect any suspicious activity in a larger correlation context. * The information (i.e., events, records, and counters) from an NSF can be used to build advanced analytics, such as behavior and predictive models to improve security posture in large deployments. * The NSF data collector can use events from the NSF for achieving high availability. It can take corrective actions such as restarting a failed NSF and horizontally scaling up the NSF. * The information (i.e., events, records, and counters) from the NSF can aid in the root cause analysis of an operational issue, so it can improve debugging. * The records from the NSF can be used to build historical data for operation and business reasons. 4. Classification of NSF Monitoring Data In order to maintain a strong security posture, it is not only necessary to configure an NSF's security policies but also to continuously monitor the NSF by checking acquirable and observable data. This enables security administrators to assess the state of the networks in a timely fashion. It is not possible to block all the internal and external threats based on static security posture. A more practical approach is supported by enabling dynamic security measures, for which continuous visibility is required. This document defines a set of monitoring elements and their scopes that can be acquired from an NSF and can be used as NSF monitoring data. In Jeong, et al. Expires 19 August 2022 [Page 5] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 essence, this monitoring data can be leveraged to support constant visibility on multiple levels of granularity and can be consumed by the corresponding functions. Three basic domains of monitoring data originating from a system entity [RFC4949], i.e., an NSF, are discussed in this document. * Retention and Emission from NSFs * Notifications for Events and Records * Push and Pull for the retrieval of monitoring data from NSFs Every system entity creates information about some context with defined I2NSF monitoring data, and so every entity can be an I2NSF component. This information is intended to be consumed by other I2NSF components, which deals with NSF monitoring data in an automated fashion. 4.1. Retention and Emission from NSFs A system entity (e.g., NSF) first retains I2NSF monitoring data inside its own system before emitting the information to another I2NSF component (e.g., NSF Data Collector). The I2NSF monitoring information consist of I2NSF Events, I2NSF Records, and I2NSF Counters as follows: I2NSF Event: I2NSF Event is defined as an important occurrence at a particular time, that is, a change in the system being managed or a change in the environment of the system being managed. An I2NSF Event requires immediate attention and should be notified as soon as possible. When used in the context of an (imperative) I2NSF Policy Rule, an I2NSF Event is used to determine whether the Condition clause of that Policy Rule can be evaluated or not. The Alarm Management Framework in [RFC3877] defines an event as something that happens which may be of interest. Examples for an event are a fault, a change in status, crossing a threshold, or an external input to the system. In the I2NSF domain, I2NSF events are created following the definition of an event in the Alarm Management Framework. I2NSF Record: A record is defined as an item of information that is kept to be looked at and used in the future. Typically, records are information generated by a system entity (e.g., NSF) that is based on operational and informational data (i.e., various changes in system characteristics), and are generated at particular instants to be kept without any changes afterward. A set of records has an ordering in time based on when they are generated. Jeong, et al. Expires 19 August 2022 [Page 6] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 Unlike I2NSF Events, records do not require immediate attention but may be useful for visibility and retroactive cyber forensics. Records are typically stored in log-files or databases on a system entity or NSF. The examples of records include as user activities, device performance, and network status. They are important for debugging, auditing, and security forensic of a system entity or the network having the system entity. I2NSF Counter: An I2NSF Counter is defined as a specific representation of an information element whose value changes very frequently. Prominent examples are network interface counters for protocol data unit (PDU) amount, byte amount, drop counters, and error counters. Counters are useful in debugging and visibility into operational behavior of a system entity (e.g., NSF). When an NSF data collector asks for the value of a counter, a system entity MUST update the counter information and emit the latest information to the NSF data collector. Retention is defined as the storing of monitoring data in NSFs. The retention of I2NSF monitoring information may be affected by the importance of the data. The importance of the data could be context- dependent, where it may not just be based on the type of data, but may also depend on where it is deployed, e.g., a test lab and testbed. The local policy and configuration will dictate the policies and procedures to review, archive, or purge the collected monitoring data. Emission is defined as the delivery of monitoring data in NSFs to an NSF data collector. The I2NSF monitoring information retained on a system entity (e.g., NSF) may be delivered to a corresponding I2NSF User via an NSF data collector. The information consists of the aggregated records, typically in the form of log-files or databases. For the NSF Monitoring Interface to deliver the information to the NSF data collector, the NSF needs to accommodate standardized delivery protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. The NSF data collector can forward the information to the I2NSF User through standardized delivery protocols (e.g., RESTCONF and NETCONF). The interface for this delivery is out of the scope of this document. 4.2. Notifications for Events and Records A specific task of an I2NSF User is to process I2NSF Policy Rules. The rules of a policy are composed of three clauses: Event, Condition, and Action clauses. In consequence, an I2NSF Event is specified to trigger the evaluation of the Condition clause of the I2NSF Policy Rule. Such an I2NSF Event is defined as an important occurrence at a particular time in the system being managed, and/or in the environment of the system being managed whose concept aligns Jeong, et al. Expires 19 August 2022 [Page 7] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 well with the generic definition of Event from [RFC3877]. Another role of the I2NSF Event is to trigger a notification for monitoring the status of an NSF. A notification is defined in [RFC3877] as an unsolicited transmission of management information. System alarm (called alarm) is defined as a warning related to service degradation in system hardware in Section 6.1. System event (called alert) is defined as a warning about any changes of configuration, any access violation, information about sessions and traffic flows in Section 6.2. Both an alarm and an alert are I2NSF Events that can be delivered as a notification. The model illustrated in this document introduces a complementary type of information that can be a conveyed notification. In I2NSF monitoring, a notification is used to deliver either an event and a record via the I2NSF Monitoring Interface. The difference between the event and record is the timing by which the notifications are emitted. An event is emitted as soon as it happens in order to notify an NSF Data Collector of the problem that needs immediate attention. A record is not emitted immediately to the NSF Data Collector, and it can be emitted periodically to the NSF Data Collector. It is important to note that an NSF Data Collector as a consumer (i.e., observer) of a notification assesses the importance of the notification rather than an NSF as a producer. The producer can include metadata in a notification that supports the observer in assessing its importance (e.g., severity). 4.3. Push and Pull for the retrieval of monitoring data from NSFs An important aspect of monitoring information is the freshness of the information. From the perspective of security, it is important to notice changes in the current status of the network. The I2NSF Monitoring Interface provides the means of sending monitored information from the NSFs to an NSF data collector in a timely manner. Monitoring information can be acquired by a client (i.e., NSF data collector) from a server (i.e., NSF) using push or pull methods. The pull is a query-based method to obtain information from the NSF. In this method, the NSF will remain passive until the information is requested from the NSF data collector. Once a request is accepted (with proper authentication), the NSF MUST update the information before sending it to the NSF data collector. Jeong, et al. Expires 19 August 2022 [Page 8] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 The push is a report-based method to obtain information from the NSF. The report-based method ensures the information can be delivered immediately without any requests. This method is used by the NSF to actively provide information to the NSF data collector. To receive the information, the NSF data collector subscribes to the NSF for the information. These acquisition methods are used for different types of monitoring information. The information that has a high level of urgency (i.e., I2NSF Event) should be provided with the push method, while information that has a lower level of urgency (i.e., I2NSF Record and I2NSF Counter) can be provided with either the pull method or push method. 5. Basic Information Model for Monitoring Data As explained in the above section, there is a wealth of data available from NSFs that can be monitored. Firstly, there must be some general information with each monitoring message sent from an NSF that helps a consumer to identify meta data with that message, which are listed as below: * message: The extra detailed description of NSF monitoring data to give an NSF data collector the context information as meta data. * vendor-name: The vendor's name of the NSF that generates the message. * device-model: The model of the device, can be represented by the device model name or serial number. This field is used to identify the model of the device that provides the security service. * software-version: The version of the software used to provide the security service. * nsf-name: The name or IP address of the NSF generating the message. If the given nsf-name is not an IP address, the name can be an arbitrary string including a FQDN (Fully Qualified Domain Name). The name MUST be unique in the scope of management domain for a different NSF to identify the NSF that generates the message. * severity: The severity level of the message. There are four levels, i.e., critical, high, middle, and low. Jeong, et al. Expires 19 August 2022 [Page 9] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * timestamp: The time when the message was generated. For the notification operations (i.e., System Alarms, System Events, NSF Events, System Logs, and NSF Logs), this is represented by the eventTime of NETCONF event notification [RFC5277] For other operations (i.e., System Counter and NSF Counter), the timestamp MUST be provided separately. * language: describes the human language intended for the user, so that it allows a user to differentiate the language that is used in the notification. This field is mandatory only when the implementation provides more than one human language for the human-readable string fields. 6. Extended Information Model for Monitoring Data The extended information model is the specific monitoring data that covers the additional information associated with the detailed information of status and performance of the network and the NSF over the basic information model. The extended information combined with the basic information creates the monitoring information (i.e., I2NSF Event, Record, and Counter). The extended monitoring information has settable characteristics for data collection as follows: * Acquisition method: The method to obtain the message. It can be a "query" or a "subscription". A "query" is a request-based method to acquire the solicited information. A "subscription" is a report-based method that pushes information to the subscriber. * Emission type: The cause type for the message to be emitted. It can be "on-change", "periodic", or "on-request". An "on-change" message is emitted when an important event happens in the NSF. A "periodic" message is emitted at a certain time interval. An "on- request" message is emitted when the information is requested. The time to periodically emit the message is configurable. * Dampening type: The type of message dampening to stop the rapid transmission of messages. The dampening types are "on-repetition" and "no-dampening". The "on-repetition" type limits the transmitted "on-change" message to one message at a certain interval (e.g., 1 second). This interval is defined as dampening- period in [RFC8641]. The dampening-period is configurable. The "no-dampening" type does not limit the transmission for the messages of the same type. In short, "on-repetition" means that the dampening is active and "no-dampening" is inactive. Activating the dampening for an "on-change" type of message is RECOMMENDED to reduce the number of messages generated. Jeong, et al. Expires 19 August 2022 [Page 10] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 6.1. System Alarms System alarms have the following characteristics: * acquisition-method: subscription * emission-type: on-change * dampening-type: on-repetition or no-dampening 6.1.1. Memory Alarm The memory is the hardware to store information temporarily or for a short period, i.e., Random Access Memory (RAM). The memory-alarm is emitted when the RAM usage exceeds the threshold. The following information should be included in a Memory Alarm: * event-name: memory-alarm. * usage: specifies the amount of memory used. * threshold: The threshold triggering the alarm * severity: The severity level of the message. There are four levels, i.e., critical, high, middle, and low. * message: Simple information as a human readable text string such as "The memory usage exceeded the threshold" or with extra information. 6.1.2. CPU Alarm CPU is the Central Processing Unit that executes basic operations of the system. The cpu-alarm is emitted when the CPU usage exceeds the threshold. The following information should be included in a CPU Alarm: * event-name: cpu-alarm. * usage: Specifies the CPU utilization. * threshold: The threshold triggering the event. * severity: The severity level of the message. There are four levels, i.e., critical, high, middle, and low. Jeong, et al. Expires 19 August 2022 [Page 11] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * message: Simple information as a human readable text string such as "The CPU usage exceeded the threshold" or with extra information. 6.1.3. Disk Alarm Disk is the hardware to store information for a long time, i.e., Hard Disk or Solid-State Drive. The disk-alarm is emitted when the Disk usage exceeds the threshold. The following information should be included in a Disk Alarm: * event-name: disk-alarm. * usage: Specifies the size of disk space used. * threshold: The threshold triggering the event. * severity: The severity level of the message. There are four levels, i.e., critical, high, middle, and low. * message: Simple information as a human readable text string such as "The disk usage exceeded the threshold" or with extra information. 6.1.4. Hardware Alarm The hardware-alarm is emitted when a hardware, e.g., CPU, memory, disk, or interface, problem is detected. The following information should be included in a Hardware Alarm: * event-name: hardware-alarm. * component-name: It indicates the hardware component responsible for generating this alarm. * severity: The severity level of the message. There are four levels, i.e., critical, high, middle, and low. * message: Simple information as a human readable text string such as "The hardware component has failed or degraded" or with extra information. 6.1.5. Interface Alarm Interface is the network interface for connecting a device with the network. The interface-alarm is emitted when the state of the interface is changed. The following information should be included in an Interface Alarm: Jeong, et al. Expires 19 August 2022 [Page 12] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * event-name: interface-alarm. * interface-name: The name of the interface. * interface-state: The status of the interface, i.e., down, up (not congested), congested (up but congested), testing, unknown, dormant, not-present, and lower-layer-down. * severity: The severity level of the message. There are total levels, i.e., critical, high, middle, and low. * message: Simple information as a human readable text string such as "The interface is 'interface-state'" or with extra information. 6.2. System Events System events (as alerts) have the following characteristics: * acquisition-method: subscription * emission-type: on-change * dampening-type: on-repetition or no-dampening 6.2.1. Access Violation The access-violation system event is an event when a user tries to access (read, write, create, or delete) any information or execute commands above their privilege. The following information should be included in this event: * event-name: access-violation. * identity: The information to identify the attempted access violation. The minimum information (extensible) that should be included: 1. user: The unique username that attempted access violation. 2. group: Group(s) to which a user belongs. A user can belong to multiple groups. 3. ip-address: The IP address of the user that triggered the event. 4. l4-port-number: The transport layer port number used by the user. Jeong, et al. Expires 19 August 2022 [Page 13] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * authentication: The method to verify the valid user, i.e., pre- configured-key and certificate-authority. * message: The message as a human readable text string to give the context of the event, such as "Access is denied". 6.2.2. Configuration Change A configuration change is a system event when a new configuration is added or an existing configuration is modified. The following information should be included in this event: * event-name: configuration-change. * identity: The information to identify the user that updated the configuration. The minimum information (extensible) that should be included: 1. user: The unique username that changes the configuration. 2. group: Group(s) to which a user belongs. A user can belong to multiple groups. 3. ip-address: The IP address of the user that triggered the event. 4. l4-port-number: The transport layer port number used by the user. * authentication: The method to verify the valid user, i.e., pre- configured-key and certificate-authority. * message: The message as a human readable text string to give the context of the event, such as "Configuration is modified", "New configuration is added", or "A configuration has been removed". * changes: Describes the modification that was made to the configuration. The minimum information that must be provided is the name of the policy that has been altered (added, modified, or removed). Other detailed information about the configuration changes is up to the implementation. Jeong, et al. Expires 19 August 2022 [Page 14] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 6.2.3. Session Table Event A session is defined as a connection (i.e., traffic flow) of a data plane (e.g., TCP, UDP, and SCTP). Session Table Event is the event triggered by the session table of an NSF. A session table holds the information of the currently active sessions. The following information should be included in a Session Table Event: * event-name: detection-session-table. * current-session: The number of concurrent sessions. * maximum-session: The maximum number of sessions that the session table can support. * threshold: The threshold triggering the event. * message: The message as a human readable text string to give the context of the event, such as "The number of sessions exceeded the table threshold". 6.2.4. Traffic Flows Traffic flows need to be monitored because they might be used for security attacks to the network. The following information should be included in this event: * event-name: traffic-flows. * interface-name: The mnemonic name of the network interface * interface-type: The type of a network interface such as an ingress or egress interface. * src-mac: The source MAC address of the traffic flow. * dst-mac: The destination MAC address of the traffic flow. * src-ip: The source IPv4 or IPv6 address of the traffic flow. * dst-ip: The destination IPv4 or IPv6 address of the traffic flow. * src-port: The transport layer source port number of the traffic flow. * dst-port: The transport layer destination port number of the traffic flow. Jeong, et al. Expires 19 August 2022 [Page 15] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * protocol: The protocol of the traffic flow. * arrival-rate: Arrival rate of packets of the traffic flow in packet per second calculated from the beginning of the flow. * arrival-throughput: Arrival rate of packets of the traffic flow in bytes per second calculated from the beginning of the flow. Note that the NSF Monitoring Interface data model is focused on a generic method to collect the monitoring information of systems and NSFs including traffic flows related to security attacks and system resource usages. On the other hand, IPFIX [RFC7011] is a standard method to collect general information on traffic flows rather than security. 6.3. NSF Events The NSF events provide the event that is detected by a specific NSF that supported a certain capability. This section only discusses the monitoring data for the advanced NSFs discussed in [I-D.ietf-i2nsf-capability-data-model]. The NSF events information can be extended to support other types of NSF. NSF events have the following characteristics: * acquisition-method: subscription * emission-type: on-change * dampening-type: on-repetition or no-dampening 6.3.1. DDoS Detection The following information should be included in a Denial-of-Service (DoS) or Distributed Denial-of-Service (DDoS) Event: * event-name: detection-ddos. * attack-type: The type of DoS or DDoS Attack, i.e., SYN flood, ACK flood, SYN-ACK flood, FIN/RST flood, TCP Connection flood, UDP flood, ICMP flood, HTTPS flood, HTTP flood, DNS query flood, DNS reply flood, SIP flood, SSL flood, and NTP amplification flood. This can be extended with additional types of DoS or DDoS attack. * attack-src-ip: The IP address of the source of the DDoS attack. * attack-dst-ip: The network prefix with a network mask (for IPv4) or prefix length (for IPv6) of a victim under DDoS attack. Jeong, et al. Expires 19 August 2022 [Page 16] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * dst-port: The port number that the attack traffic aims at. * start-time: The time stamp indicating when the attack started. * end-time: The time stamp indicating when the attack ended. If the attack is still ongoing when sending out the notification, this field can be empty. * attack-rate: The packets per second of attack traffic. * attack-throughput: The bytes per second of attack traffic. * rule-name: The name of the I2NSF Policy Rule being triggered. Note that rule-name is used to match a detected NSF event with a policy rule in [I-D.ietf-i2nsf-nsf-facing-interface-dm]. 6.3.2. Virus Event This information is used when a virus is detected within a traffic flow or inside a host. Note that "malware" is a more generic word for malicious software, including virus and worm. In the document, "virus" is used to represent "malware" such that they are interchangeable. The following information should be included in a Virus Event: * event-name: detection-virus. * virus-name: Name of the virus. * virus-type: Type of the virus. e.g., trojan, worm, macro virus type. * The following information is used only when the virus is detected within the traffic flow and not yet attacking the host: - dst-ip: The destination IP address of the flow where the virus is found. - src-ip: The source IP address of the flow where the virus is found. - src-port: The source port of the flow where the virus is found. - dst-port: The destination port of the flow where the virus is found. * The following information is used only when the virus is detected within a host system: Jeong, et al. Expires 19 August 2022 [Page 17] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 - host: The name or IP address of the host/device that is infected by the virus. If the given name is not an IP address, the name can be an arbitrary string including a FQDN (Fully Qualified Domain Name). The name MUST be unique in the scope of management domain for identifying the device that has been infected with a virus. - os: The operating system of the host that has the virus. - file-type: The type of the file where the virus is hidden. - file-name: The name of the file where the virus is hidden. * rule-name: The name of the rule being triggered. Note "host" is used only when the virus is detected within a host itself. Thus, the traffic flow information such as the source and destination IP addresses is not important, so the elements of the traffic flow (i.e., dst-ip, src-ip, src-port, and dst-port) are not specified above. On the other hand, when the virus is detected within a traffic flow and not yet attacking a host, the element of "host" is not specified above. 6.3.3. Intrusion Event The following information should be included in an Intrusion Event: * event-name: detection-intrusion. * attack-type: Attack type, e.g., brutal force or buffer overflow. * src-ip: The source IP address of the flow. * dst-ip: The destination IP address of the flow. * src-port:The source port number of the flow. * dst-port: The destination port number of the flow * protocol: The employed transport layer protocol. e.g., TCP or UDP. * app: The employed application layer protocol. e.g., HTTP or FTP. * rule-name: The name of the I2NSF Policy Rule being triggered. Jeong, et al. Expires 19 August 2022 [Page 18] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 6.3.4. Web Attack Event The following information should be included in a Web Attack Alarm: * event-name: detection-web-attack. * attack-type: Concrete web attack type. e.g., SQL injection, command injection, XSS, or CSRF. * src-ip: The source IP address of the packet. * dst-ip: The destination IP address of the packet. * src-port: The source port number of the packet. * dst-port: The destination port number of the packet. * req-method: The HTTP method of the request. For instance, "PUT" and "GET" in HTTP. * req-target: The HTTP Request Target. * response-code: The HTTP Response status code. * req-user-agent: The HTTP User-Agent header field of the request. * cookies: The HTTP Cookie header field of the request from the user agent. * req-host: The HTTP Host header field of the request. * filtering-type: URL filtering type. e.g., deny-list, allow-list, and unknown. * rule-name: The name of the I2NSF Policy Rule being triggered. 6.3.5. VoIP/VoCN Event The following information should be included in a VoIP (Voice over Internet Protocol) and VoCN (Voice over Cellular Network, such as Voice over LTE or 5G) Event: * event-name: detection-voip-vocn * source-voice-id: The detected source voice Call ID for VoIP and VoCN that violates the policy. Jeong, et al. Expires 19 August 2022 [Page 19] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * destination-voice-id: The destination voice Call ID for VoIP and VoCN that violates the policy. * user-agent: The user agent for VoIP and VoCN that violates the policy. * src-ip: The source IP address of the VoIP/VoCN. * dst-ip: The destination IP address of the VoIP/VoCN. * src-port: The source port number of the VoIP/VoCN. * dst-port: The destination port number of VoIP/VoCN. * rule-name: The name of the I2NSF Policy Rule being triggered. 6.4. System Logs System log is a record that is used to monitor the activity of the user on the NSF and the status of the NSF. System logs have the following characteristics: * acquisition-method: subscription or query * emission-type: on-change, periodic, or on-request * dampening-type: on-repetition or no-dampening 6.4.1. Access Log Access logs record administrators' login, logout, and operations on a device. By analyzing them, security vulnerabilities can be identified. The following information should be included in an operation report: * identity: The information to identify the user. The minimum information (extensible) that should be included: 1. user: The unique username that attempted access violation. 2. group: Group(s) to which a user belongs. A user can belong to multiple groups. 3. ip-address: The IP address of the user that triggered the event. 4. l4-port-number: The transport layer port number used by the user. Jeong, et al. Expires 19 August 2022 [Page 20] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * authentication: The method to verify the valid user, i.e., pre- configured-key and certificate-authority. * operation-type: The operation type that the administrator executed, e.g., login, logout, configuration, and other. * input: The operation performed by a user after login. The operation is a command given by a user. * output: The result after executing the input. 6.4.2. Resource Utilization Log Running reports record the device system's running status, which is useful for device monitoring. The following information should be included in running report: * system-status: The current system's running status. * cpu-usage: Specifies the aggregated CPU usage. * memory-usage: Specifies the memory usage. * disk-id: Specifies the disk ID to identify the storage disk. * disk-usage: Specifies the disk usage of disk-id. * disk-space-left: Specifies the available disk space left of disk- id. * session-number: Specifies total concurrent sessions. * process-number: Specifies total number of systems processes. * interface-id: Specifies the interface ID to identify the network interface. * in-traffic-rate: The total inbound data plane traffic rate in packets per second. * out-traffic-rate: The total outbound data plane traffic rate in packets per second. * in-traffic-throughput: The total inbound data plane traffic throughput in bytes per second. * out-traffic-throughput: The total outbound data plane traffic throughput in bytes per second. Jeong, et al. Expires 19 August 2022 [Page 21] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 Note that "traffic" includes only the data plane since the monitoring interface focuses on the monitoring of traffic flows for applications, rather than the control plane. In the document, "packet" includes a layer-2 frame, so "packet" and "frame" are interchangeable. 6.4.3. User Activity Log User activity logs provide visibility into users' online records (such as login time, online/lockout duration, and login IP addresses) and the actions that users perform. User activity reports are helpful to identify exceptions during a user's login and network access activities. This information should be included in a user's activity report: * identity: The information to identify the user. The minimum information (extensible) that should be included is as follows: 1. user: The unique username that attempted access violation. 2. group: Group(s) to which a user belongs. A user can belong to multiple groups. 3. ip-address: The IP address of the user that triggered the event. 4. l4-port-number: The transport layer port number used by the user. * authentication: The method to verify the valid user, i.e., pre- configured-key and certificate-authority. * online-duration: The duration of a user's activeness (stays in login) during a session. * logout-duration: The duration of a user's inactiveness (not in login) from the last session. * additional-info: Additional Information for login: 1. type: User activities. e.g., Successful User Login, Failed Login attempts, User Logout, Successful User Password Change, Failed User Password Change, User Lockout, and User Unlocking. 2. cause: Cause of a failed user activity. Jeong, et al. Expires 19 August 2022 [Page 22] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 6.5. NSF Logs NSF logs have the folowing characteristics: * acquisition-method: subscription or query * emission-type: on-change or on-request * dampening-type: on-repetition or no-dampening 6.5.1. Deep Packet Inspection Log Deep Packet Inspection (DPI) Logs provide statistics of transit traffic at an NSF such that the traffic includes uploaded and downloaded files/data, sent/received emails, and blocking/alert records on websites. It is helpful to learn risky user behaviors and why access to some URLs is blocked or allowed with an alert record. * attack-type: DPI action types. e.g., File Blocking, Data Filtering, and Application Behavior Control. * src-user: The I2NSF User's name who generates the policy. * policy-name: Security policy name that traffic matches. * action: Action defined in the file blocking rule, data filtering rule, or application behavior control rule that traffic matches. 6.6. System Counter System counter has the following characteristics: * acquisition-method: subscription or query * emission-type: periodic or on-request * dampening-type: no-dampening 6.6.1. Interface Counter Interface counters provide visibility into traffic into and out of an NSF, and bandwidth usage. The statistics of the interface counters should be computed from the start of the service up to the last measure time instant. When the service is reset, the computation of statistics per counter should use the reset time instant as the start of the service for measurement. * interface-name: Network interface name configured in NSF. Jeong, et al. Expires 19 August 2022 [Page 23] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * protocol: The type of network protocol (e.g., IPv4, IPv6, TCP, and UDP). If this field is empty, then the counter is used for all protocols. * in-total-traffic-pkts: Total inbound packets. * out-total-traffic-pkts: Total outbound packets. * in-total-traffic-bytes: Total inbound bytes. * out-total-traffic-bytes: Total outbound bytes. * in-drop-traffic-pkts: Total inbound drop packets caused by a policy or hardware/resource error. * out-drop-traffic-pkts: Total outbound drop packets caused by a policy or hardware/resource error. * in-drop-traffic-bytes: Total inbound drop bytes caused by a policy or hardware/resource error. * out-drop-traffic-bytes: Total outbound drop bytes caused by a policy or hardware/resource error. * in-traffic-average-rate: Inbound traffic average rate in packets per second. * in-traffic-peak-rate: Inbound traffic peak rate in packets per second. * in-traffic-average-throughput: Inbound traffic average throughput in bytes per second. * in-traffic-peak-throughput: Inbound traffic peak throughput in bytes per second. * out-traffic-average-rate: Outbound traffic average rate in packets per second. * out-traffic-peak-rate: Outbound traffic peak rate in packets per second. * out-traffic-average-throughput: Outbound traffic average throughput in bytes per second. * out-traffic-peak-throughput: Outbound traffic peak throughput in bytes per second. Jeong, et al. Expires 19 August 2022 [Page 24] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * discontinuity-time: The time of the most recent occasion at which any one or more of the counters suffered a discontinuity. If no such discontinuities have occurred since the last re- initialization of the local management subsystem, then this node contains the time the local management subsystem was re- initialized. 6.7. NSF Counters NSF counters have the following characteristics: * acquisition-method: subscription or query * emission-type: periodic or on-request * dampening-type: no-dampening 6.7.1. Firewall Counter Firewall counters provide visibility into traffic signatures, bandwidth usage, and how the configured security and bandwidth policies have been applied. * src-ip: Source IP address of traffic. * src-user: The I2NSF User's name who generates the policy. * dst-ip: Destination IP address of traffic. * src-port: Source port of traffic. * dst-port: Destination port of traffic. * protocol: Protocol type of traffic. * app: Application type of traffic. * policy-id: Security policy id that traffic matches. * policy-name: Security policy name that traffic matches. * in-interface: Inbound interface of traffic. * out-interface: Outbound interface of traffic. * total-traffic: Total traffic volume. Jeong, et al. Expires 19 August 2022 [Page 25] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * in-traffic-average-rate: Inbound traffic average rate in packets per second. * in-traffic-peak-rate: Inbound traffic peak rate in packets per second. * in-traffic-average-throughput: Inbound traffic average throughput in bytes per second. * in-traffic-peak-throughput: Inbound traffic peak throughput in bytes per second. * out-traffic-average-rate: Outbound traffic average rate in packets per second. * out-traffic-peak-rate: Outbound traffic peak rate in packets per second. * out-traffic-average-throughput: Outbound traffic average throughput in bytes per second. * out-traffic-peak-throughput: Outbound traffic peak throughput in bytes per second. * discontinuity-time: The time on the most recent occasion at which any one or more of the counters suffered a discontinuity. If no such discontinuities have occurred since the last re- initialization of the local management subsystem, then this node contains the time the local management subsystem was re- initialized. 6.7.2. Policy Hit Counter Policy hit counters record the security policy that traffic matches and its hit count. That is, when a packet actually matches a policy, it should be added to the statistics of a "policy hit counter" of the policy. The "policy hit counter" provides the "policy-name" that matches the policy's name in the NSF-Facing Interface YANG data model [I-D.ietf-i2nsf-nsf-facing-interface-dm]. It can check if policy configurations are correct or not. * src-ip: Source IP address of traffic. * src-user: The I2NSF User's name who generates the policy. * dst-ip: Destination IP address of traffic. * src-port: Source port of traffic. Jeong, et al. Expires 19 August 2022 [Page 26] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 * dst-port: Destination port of traffic. * protocol: Protocol type of traffic. * app: Application type of traffic. * policy-id: Security policy id that traffic matches. * policy-name: Security policy name that traffic matches. * hit-times: The number of times that the security policy matches the specified traffic. * discontinuity-time: The time on the most recent occasion at which any one or more of the counters suffered a discontinuity. If no such discontinuities have occurred since the last re- initialization of the local management subsystem, then this node contains the time the local management subsystem was re- initialized. 7. YANG Tree Structure of NSF Monitoring YANG Module The tree structure of the NSF monitoring YANG module is provided below: module: ietf-i2nsf-nsf-monitoring +--ro i2nsf-counters | +--ro language? string | +--ro system-interface* [interface-name] | | +--ro acquisition-method? identityref | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro interface-name if:interface-ref | | +--ro protocol? identityref | | +--ro in-total-traffic-pkts? yang:counter64 | | +--ro out-total-traffic-pkts? yang:counter64 | | +--ro in-total-traffic-bytes? uint64 | | +--ro out-total-traffic-bytes? uint64 | | +--ro in-drop-traffic-pkts? yang:counter64 | | +--ro out-drop-traffic-pkts? yang:counter64 | | +--ro in-drop-traffic-bytes? uint64 | | +--ro out-drop-traffic-bytes? uint64 | | +--ro discontinuity-time yang:date-and-time | | +--ro total-traffic? yang:counter64 | | +--ro in-traffic-average-rate? uint32 | | +--ro in-traffic-peak-rate? uint32 | | +--ro in-traffic-average-throughput? uint64 | | +--ro in-traffic-peak-throughput? uint64 Jeong, et al. Expires 19 August 2022 [Page 27] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 | | +--ro out-traffic-average-rate? uint32 | | +--ro out-traffic-peak-rate? uint32 | | +--ro out-traffic-average-throughput? uint64 | | +--ro out-traffic-peak-throughput? uint64 | | +--ro message? string | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | | +--ro timestamp? yang:date-and-time | +--ro nsf-firewall* [policy-name] | | +--ro acquisition-method? identityref | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro policy-name -> /nsfintf:i2nsf-security-policy/name | | +--ro src-user? string | | +--ro discontinuity-time yang:date-and-time | | +--ro total-traffic? yang:counter64 | | +--ro in-traffic-average-rate? uint32 | | +--ro in-traffic-peak-rate? uint32 | | +--ro in-traffic-average-throughput? uint64 | | +--ro in-traffic-peak-throughput? uint64 | | +--ro out-traffic-average-rate? uint32 | | +--ro out-traffic-peak-rate? uint32 | | +--ro out-traffic-average-throughput? uint64 | | +--ro out-traffic-peak-throughput? uint64 | | +--ro message? string | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | | +--ro timestamp? yang:date-and-time | +--ro nsf-policy-hits* [policy-name] | +--ro acquisition-method? identityref | +--ro emission-type? identityref | +--ro dampening-type? identityref | +--ro policy-name -> /nsfintf:i2nsf-security-policy/name | +--ro src-user? string | +--ro message? string | +--ro vendor-name? string | +--ro nsf-name? union | +--ro severity? severity | +--ro discontinuity-time yang:date-and-time | +--ro hit-times? yang:counter64 | +--ro timestamp? yang:date-and-time +--rw i2nsf-monitoring-configuration +--rw i2nsf-system-detection-alarm | +--rw enabled? boolean | +--rw system-alarm* [alarm-type] | +--rw alarm-type enumeration Jeong, et al. Expires 19 August 2022 [Page 28] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 | +--rw threshold? uint8 | +--rw dampening-period? uint32 +--rw i2nsf-system-detection-event | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-traffic-flows | +--rw dampening-period? uint32 | +--rw enabled? boolean +--rw i2nsf-nsf-detection-ddos {i2nsf-nsf-detection-ddos}? | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-nsf-detection-session-table | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-nsf-detection-intrusion {i2nsf-nsf-detection-intrusion}? | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-nsf-detection-web-attack {i2nsf-nsf-detection-web-attack}? | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-nsf-system-access-log | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-system-res-util-log | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-system-user-activity-log | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-nsf-log-dpi {i2nsf-nsf-log-dpi}? | +--rw enabled? boolean | +--rw dampening-period? uint32 +--rw i2nsf-counter +--rw period? uint16 notifications: +---n i2nsf-event | +--ro language? string | +--ro (sub-event-type)? | +--:(i2nsf-system-detection-alarm) | | +--ro i2nsf-system-detection-alarm | | +--ro alarm-category? identityref | | +--ro component-name? string | | +--ro interface-name? if:interface-ref | | +--ro interface-state? enumeration | | +--ro acquisition-method? identityref Jeong, et al. Expires 19 August 2022 [Page 29] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro usage? uint8 | | +--ro threshold? uint8 | | +--ro message? string | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | +--:(i2nsf-system-detection-event) | | +--ro i2nsf-system-detection-event | | +--ro event-category? identityref | | +--ro acquisition-method? identityref | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro user string | | +--ro group* string | | +--ro ip-address inet:ip-address-no-zone | | +--ro l4-port-number inet:port-number | | +--ro authentication? identityref | | +--ro message? string | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | | +--ro changes* [policy-name] | | +--ro policy-name -> /nsfintf:i2nsf-security-policy/name | +--:(i2nsf-traffic-flows) | | +--ro i2nsf-traffic-flows | | +--ro interface-name? if:interface-ref | | +--ro interface-type? enumeration | | +--ro src-mac? yang:mac-address | | +--ro dst-mac? yang:mac-address | | +--ro src-ip? inet:ip-address-no-zone | | +--ro dst-ip? inet:ip-address-no-zone | | +--ro protocol? identityref | | +--ro src-port? inet:port-number | | +--ro dst-port? inet:port-number | | +--ro arrival-rate? uint32 | | +--ro arrival-throughput? uint32 | | +--ro acquisition-method? identityref | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro message? string | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | +--:(i2nsf-nsf-detection-session-table) | +--ro i2nsf-nsf-detection-session-table Jeong, et al. Expires 19 August 2022 [Page 30] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 | +--ro current-session? uint32 | +--ro maximum-session? uint32 | +--ro threshold? uint32 | +--ro message? string | +--ro vendor-name? string | +--ro nsf-name? union | +--ro severity? severity +---n i2nsf-log | +--ro language? string | +--ro (sub-logs-type)? | +--:(i2nsf-nsf-system-access-log) | | +--ro i2nsf-nsf-system-access-log | | +--ro user string | | +--ro group* string | | +--ro ip-address inet:ip-address-no-zone | | +--ro l4-port-number inet:port-number | | +--ro authentication? identityref | | +--ro operation-type? operation-type | | +--ro input? string | | +--ro output? string | | +--ro acquisition-method? identityref | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro message? string | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | +--:(i2nsf-system-res-util-log) | | +--ro i2nsf-system-res-util-log | | +--ro system-status? enumeration | | +--ro cpu-usage? uint8 | | +--ro memory-usage? uint8 | | +--ro disk* [disk-id] | | | +--ro disk-id string | | | +--ro disk-usage? uint8 | | | +--ro disk-space-left? uint8 | | +--ro session-num? uint32 | | +--ro process-num? uint32 | | +--ro interface* [interface-id] | | | +--ro interface-id string | | | +--ro in-traffic-rate? uint32 | | | +--ro out-traffic-rate? uint32 | | | +--ro in-traffic-throughput? uint64 | | | +--ro out-traffic-throughput? uint64 | | +--ro acquisition-method? identityref | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro message? string Jeong, et al. Expires 19 August 2022 [Page 31] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | +--:(i2nsf-system-user-activity-log) | | +--ro i2nsf-system-user-activity-log | | +--ro acquisition-method? identityref | | +--ro emission-type? identityref | | +--ro dampening-type? identityref | | +--ro user string | | +--ro group* string | | +--ro ip-address inet:ip-address-no-zone | | +--ro l4-port-number inet:port-number | | +--ro authentication? identityref | | +--ro message? string | | +--ro vendor-name? string | | +--ro nsf-name? union | | +--ro severity? severity | | +--ro online-duration? uint32 | | +--ro logout-duration? uint32 | | +--ro additional-info? enumeration | +--:(i2nsf-nsf-log-dpi) {i2nsf-nsf-log-dpi}? | +--ro i2nsf-nsf-log-dpi | +--ro attack-type? dpi-type | +--ro acquisition-method? identityref | +--ro emission-type? identityref | +--ro dampening-type? identityref | +--ro policy-name -> /nsfintf:i2nsf-security-policy/name | +--ro src-user? string | +--ro message? string | +--ro vendor-name? string | +--ro nsf-name? union | +--ro severity? severity +---n i2nsf-nsf-event +--ro language? string +--ro (sub-event-type)? +--:(i2nsf-nsf-detection-ddos) {i2nsf-nsf-detection-ddos}? | +--ro i2nsf-nsf-detection-ddos | +--ro attack-type? identityref | +--ro start-time yang:date-and-time | +--ro end-time? yang:date-and-time | +--ro attack-src-ip* inet:ip-address-no-zone | +--ro attack-dst-ip* inet:ip-address-no-zone | +--ro attack-src-port* inet:port-number | +--ro attack-dst-port* inet:port-number | +--ro rule-name -> /nsfintf:i2nsf-security-policy/rules/name | +--ro attack-rate? uint32 Jeong, et al. Expires 19 August 2022 [Page 32] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 | +--ro attack-throughput? uint64 | +--ro action* log-action | +--ro acquisition-method? identityref | +--ro emission-type? identityref | +--ro dampening-type? identityref | +--ro message? string | +--ro vendor-name? string | +--ro nsf-name? union | +--ro severity? severity +--:(i2nsf-nsf-detection-virus) {i2nsf-nsf-detection-virus}? | +--ro i2nsf-nsf-detection-virus | +--ro dst-ip? inet:ip-address-no-zone | +--ro dst-port? inet:port-number | +--ro rule-name -> /nsfintf:i2nsf-security-policy/rules/name | +--ro src-ip? inet:ip-address-no-zone | +--ro src-port? inet:port-number | +--ro virus-name? string | +--ro virus-type? identityref | +--ro host? union | +--ro file-type? string | +--ro file-name? string | +--ro os? string | +--ro action* log-action | +--ro acquisition-method? identityref | +--ro emission-type? identityref | +--ro dampening-type? identityref | +--ro message? string | +--ro vendor-name? string | +--ro nsf-name? union | +--ro severity? severity +--:(i2nsf-nsf-detection-intrusion) {i2nsf-nsf-detection-intrusion}? | +--ro i2nsf-nsf-detection-intrusion | +--ro dst-ip? inet:ip-address-no-zone | +--ro dst-port? inet:port-number | +--ro rule-name -> /nsfintf:i2nsf-security-policy/rules/name | +--ro src-ip? inet:ip-address-no-zone | +--ro src-port? inet:port-number | +--ro protocol? identityref | +--ro app? identityref | +--ro attack-type? identityref | +--ro action* log-action | +--ro attack-rate? uint32 | +--ro attack-throughput? uint64 | +--ro acquisition-method? identityref Jeong, et al. Expires 19 August 2022 [Page 33] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 | +--ro emission-type? identityref | +--ro dampening-type? identityref | +--ro message? string | +--ro vendor-name? string | +--ro nsf-name? union | +--ro severity? severity +--:(i2nsf-nsf-detection-web-attack) {i2nsf-nsf-detection-web-attack}? | +--ro i2nsf-nsf-detection-web-attack | +--ro dst-ip? inet:ip-address-no-zone | +--ro dst-port? inet:port-number | +--ro rule-name -> /nsfintf:i2nsf-security-policy/rules/name | +--ro src-ip? inet:ip-address-no-zone | +--ro src-port? inet:port-number | +--ro attack-type? identityref | +--ro req-method? identityref | +--ro req-target? string | +--ro filtering-type* identityref | +--ro req-user-agent? string | +--ro cookie? string | +--ro req-host? string | +--ro response-code? string | +--ro acquisition-method? identityref | +--ro emission-type? identityref | +--ro dampening-type? identityref | +--ro action* log-action | +--ro message? string | +--ro vendor-name? string | +--ro nsf-name? union | +--ro severity? severity +--:(i2nsf-nsf-detection-voip-vocn) {i2nsf-nsf-detection-voip-vocn}? +--ro i2nsf-nsf-detection-voip-vocn +--ro dst-ip? inet:ip-address-no-zone +--ro dst-port? inet:port-number +--ro rule-name -> /nsfintf:i2nsf-security-policy/rules/name +--ro src-ip? inet:ip-address-no-zone +--ro src-port? inet:port-number +--ro source-voice-id* string +--ro destination-voice-id* string +--ro user-agent* string +--ro message? string +--ro vendor-name? string +--ro nsf-name? union +--ro severity? severity Jeong, et al. Expires 19 August 2022 [Page 34] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 Figure 1: NSF Monitoring YANG Module Tree 8. YANG Data Model of NSF Monitoring YANG Module This section describes a YANG module of I2NSF NSF Monitoring. The data model provided in this document uses identities to be used to get information of the monitored of an NSF's monitoring data. Every identity used in the document gives information or status about the current situation of an NSF. This YANG module imports from [RFC6991], [RFC8343], and [I-D.ietf-i2nsf-nsf-facing-interface-dm], and makes references to [RFC0768] [RFC0791] [RFC0792] [RFC0793] [RFC0854] [RFC1939] [RFC0959] [RFC2595] [RFC4340] [RFC4443] [RFC5321] [RFC5646] [RFC6242] [RFC6265] [RFC8200] [RFC8641] [RFC9051] [I-D.ietf-httpbis-http2bis] [I-D.ietf-httpbis-messaging] [I-D.ietf-httpbis-semantics] [I-D.ietf-tcpm-rfc793bis] [I-D.ietf-tsvwg-rfc4960-bis] [IANA-HTTP-Status-Code] [IANA-Media-Types]. file "ietf-i2nsf-nsf-monitoring@2022-02-15.yang" module ietf-i2nsf-nsf-monitoring { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring"; prefix nsfmi; import ietf-inet-types{ prefix inet; reference "Section 4 of RFC 6991"; } import ietf-yang-types { prefix yang; reference "Section 3 of RFC 6991"; } import ietf-i2nsf-policy-rule-for-nsf { prefix nsfintf; reference "Section 4.1 of draft-ietf-i2nsf-nsf-facing-interface-dm-17"; } import ietf-interfaces { prefix if; reference "Section 5 of RFC 8343"; } organization "IETF I2NSF (Interface to Network Security Functions) Working Group"; Jeong, et al. Expires 19 August 2022 [Page 35] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 contact "WG Web: WG List: Editor: Jaehoon Paul Jeong Editor: Patrick Lingga "; description "This module is a YANG module for I2NSF NSF Monitoring. The key words 'MUST', 'MUST NOT', 'REQUIRED', 'SHALL', 'SHALL NOT', 'SHOULD', 'SHOULD NOT', 'RECOMMENDED', 'NOT RECOMMENDED', 'MAY', and 'OPTIONAL' in this document are to be interpreted as described in BCP 14 (RFC 2119) (RFC 8174) when, and only when, they appear in all capitals, as shown here. Copyright (c) 2022 IETF Trust and the persons identified as authors of the code. All rights reserved. Redistribution and use in source and binary forms, with or without modification, is permitted pursuant to, and subject to the license terms contained in, the Simplified BSD License set forth in Section 4.c of the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/license-info). This version of this YANG module is part of RFC XXXX (https://www.rfc-editor.org/info/rfcXXXX); see the RFC itself for full legal notices."; revision "2022-02-15" { description "Latest revision"; reference "RFC XXXX: I2NSF NSF Monitoring Interface YANG Data Model"; // RFC Ed.: replace XXXX with an actual RFC number and remove // this note. } /* * Typedefs */ typedef severity { Jeong, et al. Expires 19 August 2022 [Page 36] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 type enumeration { enum critical { description "The 'critical' severity level indicates that an immediate corrective action is required. A 'critical' severity is reported when a service becomes totally out of service and must be restored."; } enum high { description "The 'high' severity level indicates that an urgent corrective action is required. A 'high' severity is reported when there is a severe degradation in the capability of the service and its full capability must be restored."; } enum middle { description "The 'middle' severity level indicates the existence of a non-service-affecting fault condition and corrective action should be done to prevent a more serious fault. The 'middle' severity is reported when the detected problem is not degrading the capability of the service, but some service degradation might happen if not prevented."; } enum low { description "The 'low' severity level indicates the detection of a potential fault before any effect is observed. The 'low' severity is reported when an action should be done before a fault happen."; } } description "An indicator representing severity levels. The severity levels starting from the highest are critical, high, middle, and low."; } typedef log-action { type enumeration { enum allow { description "If action is allow"; } enum alert { Jeong, et al. Expires 19 August 2022 [Page 37] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 description "If action is alert"; } enum block { description "If action is block"; } enum discard { description "If action is discard"; } enum declare { description "If action is declare"; } enum block-ip { description "If action is block-ip"; } enum block-service{ description "If action is block-service"; } } description "The type representing action for logging."; } typedef dpi-type{ type enumeration { enum file-blocking{ description "DPI for preventing the specified file types from flowing in the network."; } enum data-filtering{ description "DPI for preventing sensitive information (e.g., Credit Card Number or Social Security Numbers) leaving a protected network."; } enum application-behavior-control{ description "DPI for filtering packet based on the application or network behavior analysis to identify malicious or unusual activity."; } Jeong, et al. Expires 19 August 2022 [Page 38] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } description "The type of Deep Packet Inspection (DPI). The defined types are file-blocking, data-filtering, and application-behavior-control."; } typedef operation-type{ type enumeration { enum login { description "The operation type is Login."; } enum logout { description "The operation type is Logout."; } enum configuration { description "The operation type is Configuration. The configuration operation includes the command for writing a new configuration and modifying an existing configuration."; } enum other { description "The operation type is Other operation. This other includes all operations done by a user except login, logout, and configuration."; } } description "The type of operation done by a user during a session. The user operation is not considering their privileges."; } typedef login-role { type enumeration { enum administrator { description "Administrator (i.e., Superuser)'s login role. Non-restricted role."; } enum user { description "User login role. Semi-restricted role, some data and configurations are available but confidential or important data and configuration are restricted."; } Jeong, et al. Expires 19 August 2022 [Page 39] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 enum guest { description "Guest login role. Restricted role, only few read data are available and write configurations are restricted."; } } description "The privilege level of the user account."; } /* * Identity */ identity characteristics { description "Base identity for monitoring information characteristics"; } identity acquisition-method { base characteristics; description "The type of acquisition-method. It can be multiple types at once."; } identity subscription { base acquisition-method; description "The acquisition-method type is subscription."; } identity query { base acquisition-method; description "The acquisition-method type is query."; } identity emission-type { base characteristics; description "The type of emission-type."; } identity periodic { base emission-type; description "The emission-type type is periodic."; } identity on-change { base emission-type; description Jeong, et al. Expires 19 August 2022 [Page 40] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "The emission-type type is on-change."; } identity on-request { base emission-type; description "The emission-type type is on-request."; } identity dampening-type { base characteristics; description "The type of message dampening to stop the rapid transmission of messages. The dampening types are on-repetition and no-dampening"; } identity no-dampening { base dampening-type; description "The dampening-type is no-dampening. No-dampening type does not limit the transmission for the messages of the same type."; } identity on-repetition { base dampening-type; description "The dampening-type is on-repetition. On-repetition type limits the transmitted on-change message to one message at a certain interval."; } identity authentication-mode { description "The authentication mode for a user to connect to the NSF, e.g., pre-configured-key and certificate-authority"; } identity pre-configured-key { base authentication-mode; description "The pre-configured-key is an authentication using a key authentication."; } identity certificate-authority { base authentication-mode; description "The certificate-authority (CA) is an authentication using a digital certificate."; } identity event { Jeong, et al. Expires 19 August 2022 [Page 41] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 description "Base identity for I2NSF events."; } identity system-event { base event; description "Identity for system event"; } identity system-alarm { base event; description "Base identity for detectable system alarm types"; } identity memory-alarm { base system-alarm; description "A memory alarm is alerted."; } identity cpu-alarm { base system-alarm; description "A CPU alarm is alerted."; } identity disk-alarm { base system-alarm; description "A disk alarm is alerted."; } identity hardware-alarm { base system-alarm; description "A hardware alarm (i.e., hardware failure) is alerted."; } identity interface-alarm { base system-alarm; description "An interface alarm is alerted."; } identity access-violation { base system-event; description "The access-violation system event is an event when a user tries to access (read, write, create, or delete) any information or execute commands above their privilege."; Jeong, et al. Expires 19 August 2022 [Page 42] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } identity configuration-change { base system-event; description "The configuration-change system event is an event when a user adds a new configuration or modify an existing configuration (write configuration)."; } identity attack-type { description "The root ID of attack-based notification in the notification taxonomy"; } identity nsf-attack-type { base attack-type; description "This ID is intended to be used in the context of NSF event."; } identity virus-type { base nsf-attack-type; description "The type of virus. It can be multiple types at once. This attack type is associated with a detected system-log virus-attack."; } identity trojan { base virus-type; description "The virus type is a trojan. Trojan is able to disguise the intent of the files or programs to misleads the users."; } identity worm { base virus-type; description "The virus type is a worm. Worm can self-replicate and spread through the network automatically."; } identity macro { base virus-type; description "The virus type is a macro virus. Macro causes a series of threats automatically after the program is executed."; } identity boot-sector { base virus-type; Jeong, et al. Expires 19 August 2022 [Page 43] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 description "The virus type is a boot sector virus. Boot sector is a virus that infects the core of the computer, affecting the startup process."; } identity polymorphic { base virus-type; description "The virus type is a polymorphic virus. Polymorphic can modify its version when it replicates, making it hard to detect."; } identity overwrite { base virus-type; description "The virus type is an overwrite virus. Overwrite can remove existing software and replace it with malicious code by overwriting it."; } identity resident { base virus-type; description "The virus-type is a resident virus. Resident saves itself in the computer's memory and infects other files and software."; } identity non-resident { base virus-type; description "The virus-type is a non-resident virus. Non-resident attaches directly to an executable file and enters the device when executed."; } identity multipartite { base virus-type; description "The virus-type is a multipartite virus. Multipartite attacks both the boot sector and executables files of a computer."; } identity spacefiller { base virus-type; description "The virus-type is a spacefiller virus. Spacefiller fills empty spaces of a file or software with malicious code."; } identity intrusion-attack-type { base nsf-attack-type; description Jeong, et al. Expires 19 August 2022 [Page 44] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "The attack type is associated with a detected system-log intrusion."; } identity brute-force { base intrusion-attack-type; description "The intrusion type is brute-force."; } identity buffer-overflow { base intrusion-attack-type; description "The intrusion type is buffer-overflow."; } identity web-attack-type { base nsf-attack-type; description "The attack type is associated with a detected system-log web-attack."; } identity command-injection { base web-attack-type; description "The detected web attack type is command injection."; } identity xss { base web-attack-type; description "The detected web attack type is Cross Site Scripting (XSS)."; } identity csrf { base web-attack-type; description "The detected web attack type is Cross Site Request Forgery."; } identity ddos-type { base nsf-attack-type; description "Base identity for detectable flood types"; } identity syn-flood { base ddos-type; description "A SYN flood is detected."; } identity ack-flood { base ddos-type; description Jeong, et al. Expires 19 August 2022 [Page 45] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "An ACK flood is detected."; } identity syn-ack-flood { base ddos-type; description "A SYN-ACK flood is detected."; } identity fin-rst-flood { base ddos-type; description "A FIN-RST flood is detected."; } identity tcp-con-flood { base ddos-type; description "A TCP connection flood is detected."; } identity udp-flood { base ddos-type; description "A UDP flood is detected."; } identity icmpv4-flood { base ddos-type; description "An ICMPv4 flood is detected."; } identity icmpv6-flood { base ddos-type; description "An ICMPv6 flood is detected."; } identity http-flood { base ddos-type; description "An HTTP flood is detected."; } identity https-flood { base ddos-type; description "An HTTPS flood is detected."; } identity dns-query-flood { base ddos-type; description "A Domain Name System (DNS) query flood is detected."; } identity dns-reply-flood { Jeong, et al. Expires 19 August 2022 [Page 46] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 base ddos-type; description "A Domain Name System (DNS) reply flood is detected."; } identity sip-flood { base ddos-type; description "A Session Initiation Protocol (SIP) flood is detected."; } identity tls-flood { base ddos-type; description "A Transport Layer Security (TLS) flood is detected"; } identity ntp-amp-flood { base ddos-type; description "A Network Time Protocol (NTP) amplification is detected"; } identity req-method { description "A set of request types in HTTP (if applicable)."; } identity put { base req-method; description "The detected request type is PUT."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method PUT"; } identity post { base req-method; description "The detected request type is POST."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method POST"; } identity get { base req-method; description "The detected request type is GET."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method GET"; } Jeong, et al. Expires 19 August 2022 [Page 47] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 identity head { base req-method; description "The detected request type is HEAD."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method HEAD"; } identity delete { base req-method; description "The detected request type is DELETE."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method DELETE"; } identity connect { base req-method; description "The detected request type is CONNECT."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method CONNECT"; } identity options { base req-method; description "The detected request type is OPTIONS."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method OPTIONS"; } identity trace { base req-method; description "The detected request type is TRACE."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Method TRACE"; } identity filter-type { description "The type of filter used to detect an attack, for example, a web-attack. It can be applicable to more than web-attacks."; } identity allow-list { Jeong, et al. Expires 19 August 2022 [Page 48] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 base filter-type; description "The applied filter type is an allow list. This filter blocks all connection except the specified list."; } identity deny-list { base filter-type; description "The applied filter type is a deny list. This filter opens all connection except the specified list."; } identity unknown-filter { base filter-type; description "The applied filter is unknown."; } identity protocol { description "An identity used to enable type choices in leaves and leaflists with respect to protocol metadata. This is used to identify the type of protocol that goes through the NSF."; } identity ip { base protocol; description "General IP protocol type."; reference "RFC 791: Internet Protocol RFC 8200: Internet Protocol, Version 6 (IPv6)"; } identity ipv4 { base ip; description "IPv4 protocol type."; reference "RFC 791: Internet Protocol"; } identity ipv6 { base ip; description "IPv6 protocol type."; reference "RFC 8200: Internet Protocol, Version 6 (IPv6)"; } identity icmp { base protocol; description Jeong, et al. Expires 19 August 2022 [Page 49] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "Base identity for ICMPv4 and ICMPv6 condition capability"; reference "RFC 792: Internet Control Message Protocol RFC 4443: Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification - ICMPv6"; } identity icmpv4 { base icmp; description "ICMPv4 protocol type."; reference "RFC 791: Internet Protocol RFC 792: Internet Control Message Protocol"; } identity icmpv6 { base icmp; description "ICMPv6 protocol type."; reference "RFC 8200: Internet Protocol, Version 6 (IPv6) RFC 4443: Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification"; } identity transport-protocol { base protocol; description "Base identity for Layer 4 protocol condition capabilities, e.g., TCP, UDP, SCTP, DCCP, and ICMP"; } identity tcp { base transport-protocol; description "TCP protocol type."; reference "RFC 793: Transmission Control Protocol draft-ietf-tcpm-rfc793bis-25: Transmission Control Protocol (TCP) Specification"; } identity udp { base transport-protocol; description "UDP protocol type."; reference "RFC 768: User Datagram Protocol"; } identity sctp { Jeong, et al. Expires 19 August 2022 [Page 50] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 base transport-protocol; description "Identity for SCTP condition capabilities"; reference "draft-ietf-tsvwg-rfc4960-bis-18: Stream Control Transmission Protocol"; } identity dccp { base transport-protocol; description "Identity for DCCP condition capabilities"; reference "RFC 4340: Datagram Congestion Control Protocol"; } identity application-protocol { base protocol; description "Base identity for Application protocol. Note that popular application protocols (e.g., HTTP, HTTPS, FTP, POP3, and IMAP) are handled in this YANG module, rather than all the existing application protocols."; } identity http { base application-protocol; description "The identity for Hypertext Transfer Protocol version 1.X (HTTP/1.X)."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics draft-ietf-httpbis-messaging-19: HTTP/1.1"; } identity https { base application-protocol; description "The identity for Hypertext Transfer Protocol version 1.X (HTTP/1.X) over TLS."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics draft-ietf-httpbis-messaging-19: HTTP/1.1"; } identity http2 { base application-protocol; description "The identity for Hypertext Transfer Protocol version 2 (HTTP/2)."; reference "draft-ietf-httpbis-http2bis-07: HTTP/2"; } Jeong, et al. Expires 19 August 2022 [Page 51] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 identity https2 { base application-protocol; description "The identity for Hypertext Transfer Protocol version 2 (HTTP/2) over TLS."; reference "draft-ietf-httpbis-http2bis-07: HTTP/2"; } identity ftp { base application-protocol; description "FTP protocol type."; reference "RFC 959: File Transfer Protocol"; } identity ssh { base application-protocol; description "SSH protocol type."; reference "RFC 6242: Using the NETCONF Protocol over Secure Shell (SSH)"; } identity telnet { base application-protocol; description "The identity for telnet."; reference "RFC 854: Telnet Protocol"; } identity smtp { base application-protocol; description "The identity for smtp."; reference "RFC 5321: Simple Mail Transfer Protocol (SMTP)"; } identity pop3 { base application-protocol; description "The identity for Post Office Protocol 3 (POP3)."; reference "RFC 1939: Post Office Protocol - Version 3 (POP3)"; } identity pop3s { base application-protocol; description "The identity for Post Office Protocol 3 (POP3) over TLS"; reference Jeong, et al. Expires 19 August 2022 [Page 52] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "RFC 1939: Post Office Protocol - Version 3 (POP3) RFC 2595: Using TLS with IMAP, POP3 and ACAP"; } identity imap { base application-protocol; description "The identity for Internet Message Access Protocol (IMAP)."; reference "RFC 9051: Internet Message Access Protocol (IMAP) - Version 4rev2"; } identity imaps { base application-protocol; description "The identity for Internet Message Access Protocol (IMAP) over TLS"; reference "RFC 9051: Internet Message Access Protocol (IMAP) - Version 4rev2 RFC 2595: Using TLS with IMAP, POP3 and ACAP"; } /* * Grouping */ grouping timestamp { description "Grouping for identifying the time of the message."; leaf timestamp { type yang:date-and-time; description "Specify the time of a message being delivered."; } } grouping common-monitoring-data { description "A set of common monitoring data that is needed as the basic information."; leaf message { type string; description "This is a freetext annotation for monitoring a notification's content."; } leaf vendor-name { type string; Jeong, et al. Expires 19 August 2022 [Page 53] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 description "The name of the NSF vendor. The string is unrestricted to identify the provider or vendor of the NSF."; } leaf nsf-name { type union { type string; type inet:ip-address-no-zone; } description "The name or IP address of the NSF generating the message. If the given nsf-name is not an IP address, the name can be an arbitrary string including a FQDN (Fully Qualified Domain Name). The name MUST be unique in the scope of management domain for a different NSF to identify the NSF that generates the message."; } leaf severity { type severity; description "The severity of the alarm such as critical, high, middle, and low."; } } grouping characteristics { description "A set of characteristics of a notification."; leaf acquisition-method { type identityref { base acquisition-method; } description "The acquisition-method for characteristics"; } leaf emission-type { type identityref { base emission-type; } description "The emission-type for characteristics"; } leaf dampening-type { type identityref { base dampening-type; } description "The dampening-type for characteristics"; } Jeong, et al. Expires 19 August 2022 [Page 54] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } grouping i2nsf-system-alarm-type-content { description "A set of contents for alarm type notification."; leaf usage { type uint8 { range "0..100"; } units "percent"; description "Specifies the used percentage"; } leaf threshold { type uint8 { range "0..100"; } units "percent"; description "The threshold percentage triggering the alarm or the event"; } } grouping i2nsf-system-event-type-content { description "System event metadata associated with system events caused by user activity. This can be extended to provide additional information."; leaf user { type string; mandatory true; description "The name of a user"; } leaf-list group { type string; min-elements 1; description "The group(s) to which a user belongs."; } leaf ip-address { type inet:ip-address-no-zone; mandatory true; description "The IPv4 (or IPv6) address of a user that trigger the event."; } leaf l4-port-number { type inet:port-number; Jeong, et al. Expires 19 August 2022 [Page 55] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 mandatory true; description "The transport layer port number used by the user."; } leaf authentication { type identityref { base authentication-mode; } description "The authentication-mode of a user."; } } grouping i2nsf-nsf-event-type-content { description "A set of common IPv4 (or IPv6)-related NSF event content elements"; leaf dst-ip { type inet:ip-address-no-zone; description "The destination IPv4 (IPv6) address of the packet"; } leaf dst-port { type inet:port-number; description "The destination port of the packet"; } leaf rule-name { type leafref { path "/nsfintf:i2nsf-security-policy" +"/nsfintf:rules/nsfintf:name"; } mandatory true; description "The name of the I2NSF Policy Rule being triggered"; } } grouping i2nsf-nsf-event-type-content-extend { description "A set of extended common IPv4 (or IPv6)-related NSF event content elements"; uses i2nsf-nsf-event-type-content; leaf src-ip { type inet:ip-address-no-zone; description "The source IPv4 (or IPv6) address of the packet or flow"; } leaf src-port { Jeong, et al. Expires 19 August 2022 [Page 56] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 type inet:port-number; description "The source port of the packet or flow"; } } grouping log-action { description "A grouping for logging action."; leaf-list action { type log-action; description "Action type: allow, alert, block, discard, declare, block-ip, block-service"; } } grouping attack-rates { description "A set of traffic rates for monitoring attack traffic data"; leaf attack-rate { type uint32; units "pps"; description "The average packets per second (pps) rate of attack traffic"; } leaf attack-throughput { type uint64; units "Bps"; description "The average bytes per second (Bps) throughput of attack traffic"; } } grouping traffic-rates { description "A set of traffic rates for statistics data"; leaf discontinuity-time { type yang:date-and-time; mandatory true; description "The time on the most recent occasion at which any one or more of the counters suffered a discontinuity. If no such discontinuities have occurred since the last re-initialization of the local management subsystem, then this node contains the time the local management subsystem was re-initialized."; } Jeong, et al. Expires 19 August 2022 [Page 57] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 leaf total-traffic { type yang:counter64; units "packets"; description "The total number of traffic packets (in and out) in the NSF."; } leaf in-traffic-average-rate { type uint32; units "pps"; description "Inbound traffic average rate in packets per second (pps). The average is calculated from the start of the NSF service until the generation of this record."; } leaf in-traffic-peak-rate { type uint32; units "pps"; description "Inbound traffic peak rate in packets per second (pps)."; } leaf in-traffic-average-throughput { type uint64; units "Bps"; description "Inbound traffic average throughput in bytes per second (Bps). The average is calculated from the start of the NSF service until the generation of this record."; } leaf in-traffic-peak-throughput { type uint64; units "Bps"; description "Inbound traffic peak throughput in bytes per second (Bps)."; } leaf out-traffic-average-rate { type uint32; units "pps"; description "Outbound traffic average rate in packets per second (pps). The average is calculated from the start of the NSF service until the generation of this record."; } leaf out-traffic-peak-rate { type uint32; units "pps"; description "Outbound traffic peak rate in packets per second (pps)."; Jeong, et al. Expires 19 August 2022 [Page 58] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } leaf out-traffic-average-throughput { type uint64; units "Bps"; description "Outbound traffic average throughput in bytes per second (Bps). The average is calculated from the start of the NSF service until the generation of this record."; } leaf out-traffic-peak-throughput { type uint64; units "Bps"; description "Outbound traffic peak throughput in bytes per second (Bps)."; } } grouping i2nsf-system-counter-type-content{ description "A set of counters for an interface traffic data."; leaf interface-name { type if:interface-ref; description "Network interface name configured in an NSF"; reference "RFC 8343: A YANG Data Model for Interface Management"; } leaf protocol { type identityref { base protocol; } description "The type of network protocol for the interface counter. If this field is empty, then the counter includes all protocols (e.g., IPv4, IPv6, TCP, and UDP)"; } leaf in-total-traffic-pkts { type yang:counter64; description "Total inbound packets"; } leaf out-total-traffic-pkts { type yang:counter64; description "Total outbound packets"; } leaf in-total-traffic-bytes { type uint64; Jeong, et al. Expires 19 August 2022 [Page 59] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 units "bytes"; description "Total inbound bytes"; } leaf out-total-traffic-bytes { type uint64; units "bytes"; description "Total outbound bytes"; } leaf in-drop-traffic-pkts { type yang:counter64; description "Total inbound drop packets"; } leaf out-drop-traffic-pkts { type yang:counter64; description "Total outbound drop packets"; } leaf in-drop-traffic-bytes { type uint64; units "bytes"; description "Total inbound drop bytes"; } leaf out-drop-traffic-bytes { type uint64; units "bytes"; description "Total outbound drop bytes"; } uses traffic-rates; } grouping i2nsf-nsf-counters-type-content{ description "A set of contents of a policy in an NSF."; leaf policy-name { type leafref { path "/nsfintf:i2nsf-security-policy" +"/nsfintf:name"; } mandatory true; description "The name of the policy being triggered"; } Jeong, et al. Expires 19 August 2022 [Page 60] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 leaf src-user{ type string; description "The I2NSF User's name who generates the policy."; } } grouping enable-notification { description "A grouping for enabling or disabling notification"; leaf enabled { type boolean; default "true"; description "Enables or Disables the notification. If 'true', then the notification is enabled. If 'false, then the notification is disabled."; } } grouping dampening { description "A grouping for dampening period of notification."; leaf dampening-period { type uint32; units "centiseconds"; default "0"; description "Specifies the minimum interval between the assembly of successive update records for a single receiver of a subscription. Whenever subscribed objects change and a dampening-period interval (which may be zero) has elapsed since the previous update record creation for a receiver, any subscribed objects and properties that have changed since the previous update record will have their current values marshalled and placed in a new update record. But if the subscribed objects change when the dampening-period is active, it should update the record without sending the notification until the dampening- period is finished. If multiple changes happen during the active dampening-period, it should update the record with the latest data. And at the end of the dampening-period, it should send the record as a notification with the latest updated record and restart the countdown."; reference "RFC 8641: Subscription to YANG Notifications for Datastore Updates - Section 5."; } Jeong, et al. Expires 19 August 2022 [Page 61] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } grouping language { description "A grouping for language tag"; leaf language { type string { pattern "^((en-GB-oed|i-ami|i-bnn|i-default|" + "i-enochian|i-hak|i-klingon|i-lux|i-mingo|i-navajo|i-pwn|" + "i-tao|i-tay|i-tsu|sgn-BE-FR|sgn-BE-NL|sgn-CH-DE)|" + "(art-lojban|cel-gaulish|no-bok|no-nyn|zh-guoyu|zh-hakka|" + "zh-min|zh-min-nan|zh-xiang)|" + "(([A-Za-z]{2,3}(-[A-Za-z]{3}(-[A-Za-z]{3}){0,2})?)|" + "[A-Za-z]{4}|[A-Za-z]{5,8}" + "(-[A-Za-z]{4})?" + "(-[A-Za-z]{2}|[0-9]{3})?" + "(-[A-Za-z0-9]{5,8}|[0-9][A-Za-z0-9]{3})*" + "(-[0-9A-WY-Za-wy-z](-[A-Za-z0-9]{2,8})+)*" + "(-x(-[A-Za-z0-9]{1,8})+)?)|" + "x(-[A-Za-z0-9]{1,8})+)$"; } description "The value in this field describes the human language intended for the user, so that it allows a user to differentiate the language that is used in the notification. This field is mandatory only when the implementation provides more than one human language for the human-readable string fields. This field uses the language-tag production in Section 2.1 in RFC 5646. See the document for more details."; reference "RFC 5646: Tags for Identifying Languages"; } } /* * Feature Nodes */ feature i2nsf-nsf-detection-ddos { description "This feature means it supports I2NSF nsf-detection-ddos notification"; } feature i2nsf-nsf-detection-virus { description Jeong, et al. Expires 19 August 2022 [Page 62] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "This feature means it supports I2NSF nsf-detection-virus notification"; } feature i2nsf-nsf-detection-intrusion { description "This feature means it supports I2NSF nsf-detection-intrusion notification"; } feature i2nsf-nsf-detection-web-attack { description "This feature means it supports I2NSF nsf-detection-web-attack notification"; } feature i2nsf-nsf-detection-voip-vocn { description "This feature means it supports I2NSF nsf-detection-voip-vocn notification"; } feature i2nsf-nsf-log-dpi { description "This feature means it supports I2NSF nsf-log-dpi notification"; } /* * Notification nodes */ notification i2nsf-event { description "Notification for I2NSF Event."; uses language; choice sub-event-type { description "This choice must be augmented with cases for each allowed sub-event. Only 1 sub-event will be instantiated in each i2nsf-event message. Each case is expected to define one container with all the sub-event fields."; case i2nsf-system-detection-alarm { container i2nsf-system-detection-alarm{ description "This notification is sent, when a system alarm is detected."; leaf alarm-category { type identityref { base system-alarm; Jeong, et al. Expires 19 August 2022 [Page 63] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } description "The alarm category for system-detection-alarm notification"; } leaf component-name { type string; description "The hardware component responsible for generating the message. Applicable for Hardware Failure Alarm."; } leaf interface-name { type if:interface-ref; description "The interface name responsible for generating the message. Applicable for Network Interface Failure Alarm."; reference "RFC 8343: A YANG Data Model for Interface Management"; } leaf interface-state { type enumeration { enum up { value 1; description "The interface state is up and not congested. The interface is ready to pass packets."; } enum down { value 2; description "The interface state is down, i.e., does not pass any packets."; } enum congested { value 3; description "The interface state is up but congested."; } enum testing { value 4; description "In some test mode. No operational packets can be passed."; } enum unknown { value 5; Jeong, et al. Expires 19 August 2022 [Page 64] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 description "Status cannot be determined for some reason."; } enum dormant { value 6; description "Waiting for some external event."; } enum not-present { value 7; description "Some component (typically hardware) is missing."; } enum lower-layer-down { value 8; description "Down due to state of lower-layer interface(s)."; } } description "The state of the interface. Applicable for Network Interface Failure Alarm."; reference "RFC 8343: A YANG Data Model for Interface Management - Operational States"; } uses characteristics; uses i2nsf-system-alarm-type-content; uses common-monitoring-data; } } case i2nsf-system-detection-event { container i2nsf-system-detection-event { description "This notification is sent when a security-sensitive authentication action fails."; leaf event-category { type identityref { base system-event; } description "The event category for system-detection-event"; } uses characteristics; uses i2nsf-system-event-type-content; uses common-monitoring-data; list changes { Jeong, et al. Expires 19 August 2022 [Page 65] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 key policy-name; description "Describes the modification that was made to the configuration. The minimum information that must be provided is the name of the policy that has been altered (added, modified, or removed). This list can be extended with the detailed information about the specific changes made to the configuration based on the implementation."; leaf policy-name { type leafref { path "/nsfintf:i2nsf-security-policy" +"/nsfintf:name"; } description "The name of the policy configuration that has been added, modified, or removed."; } } } } case i2nsf-traffic-flows { container i2nsf-traffic-flows { description "This notification is sent to inform about the traffic flows."; leaf interface-name { type if:interface-ref; description "The mnemonic name of the network interface"; } leaf interface-type { type enumeration { enum ingress { description "The corresponding interface-name indicates an ingress interface."; } enum egress { description "The corresponding interface-name indicates an egress interface."; } } description "The type of a network interface such as an ingress or Jeong, et al. Expires 19 August 2022 [Page 66] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 egress interface."; } leaf src-mac { type yang:mac-address; description "The source MAC address of the traffic flow."; } leaf dst-mac { type yang:mac-address; description "The destination MAC address of the traffic flow."; } leaf src-ip { type inet:ip-address-no-zone; description "The source IPv4 (or IPv6) address of the flow"; } leaf dst-ip { type inet:ip-address-no-zone; description "The destination IPv4 (or IPv6) address of the flow"; } leaf protocol { type identityref { base protocol; } description "The protocol type for nsf-detection-intrusion notification"; } leaf src-port { type inet:port-number; description "The transport layer source port number of the flow"; } leaf dst-port { type inet:port-number; description "The transport layer destination port number of the flow"; } leaf arrival-rate { type uint32; units "pps"; description "The average arrival rate of the flow in packets per second. The average is calculated from the start of the NSF service until the generation of this Jeong, et al. Expires 19 August 2022 [Page 67] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 record."; } leaf arrival-throughput { type uint32; units "Bps"; description "The average arrival rate of the flow in bytes per second. The average is calculated from the start of the NSF service until the generation of this record."; } uses characteristics; uses common-monitoring-data; } } case i2nsf-nsf-detection-session-table { container i2nsf-nsf-detection-session-table { description "This notification is sent, when a session table event is detected."; leaf current-session { type uint32; description "The number of concurrent sessions"; } leaf maximum-session { type uint32; description "The maximum number of sessions that the session table can support"; } leaf threshold { type uint32; description "The threshold triggering the event"; } uses common-monitoring-data; } } } } notification i2nsf-log { description "Notification for I2NSF log. The notification is generated from the logs of the NSF."; Jeong, et al. Expires 19 August 2022 [Page 68] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 uses language; choice sub-logs-type { description "This choice must be augmented with cases for each allowed sub-logs. Only 1 sub-event will be instantiated in each i2nsf-logs message. Each case is expected to define one container with all the sub-logs fields."; case i2nsf-nsf-system-access-log { container i2nsf-nsf-system-access-log { description "The notification is sent, if there is a new system log entry about a system access event."; uses i2nsf-system-event-type-content; leaf operation-type { type operation-type; description "The operation type that the user executes"; } leaf input { type string; description "The operation performed by a user after login. The operation is a command given by a user."; } leaf output { type string; description "The result in text format after executing the input."; } uses characteristics; uses common-monitoring-data; } } case i2nsf-system-res-util-log { container i2nsf-system-res-util-log { description "This notification is sent, if there is a new log entry representing resource utilization updates."; leaf system-status { type enumeration { enum running { description "The system is active and running the security service."; } Jeong, et al. Expires 19 August 2022 [Page 69] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 enum waiting { description "The system is active but waiting for an event to provide the security service."; } enum inactive { description "The system is inactive and not running the security service."; } } description "The current system's running status"; } leaf cpu-usage { type uint8; units "percent"; description "Specifies the relative percentage of CPU utilization with respect to platform resources"; } leaf memory-usage { type uint8; units "percent"; description "Specifies the percentage of memory usage."; } list disk { key disk-id; description "Disk is the hardware to store information for a long period, i.e., Hard Disk or Solid-State Drive."; leaf disk-id { type string; description "The ID of the storage disk. It is a free form identifier to identify the storage disk."; } leaf disk-usage { type uint8; units "percent"; description "Specifies the percentage of disk usage"; } leaf disk-space-left { type uint8; units "percent"; description Jeong, et al. Expires 19 August 2022 [Page 70] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "Specifies the percentage of disk space left"; } } leaf session-num { type uint32; description "The total number of sessions"; } leaf process-num { type uint32; description "The total number of processes"; } list interface { key interface-id; description "The network interface for connecting a device with the network."; leaf interface-id { type string; description "The ID of the network interface. It is a free form identifier to identify the network interface."; } leaf in-traffic-rate { type uint32; units "pps"; description "The total inbound traffic rate in packets per second"; } leaf out-traffic-rate { type uint32; units "pps"; description "The total outbound traffic rate in packets per second"; } leaf in-traffic-throughput { type uint64; units "Bps"; description "The total inbound traffic throughput in bytes per second"; } leaf out-traffic-throughput { type uint64; units "Bps"; Jeong, et al. Expires 19 August 2022 [Page 71] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 description "The total outbound traffic throughput in bytes per second"; } } uses characteristics; uses common-monitoring-data; } } case i2nsf-system-user-activity-log { container i2nsf-system-user-activity-log { description "This notification is sent, if there is a new user activity log entry."; uses characteristics; uses i2nsf-system-event-type-content; uses common-monitoring-data; leaf online-duration { type uint32; units "seconds"; description "The duration of a user's activeness (stays in login) during a session."; } leaf logout-duration { type uint32; units "seconds"; description "The duration of a user's inactiveness (not in login) from the last session."; } leaf additional-info { type enumeration { enum successful-login { description "The user has succeeded in login."; } enum failed-login { description "The user has failed in login (e.g., wrong password)"; } enum logout { description "The user has succeeded in logout"; } Jeong, et al. Expires 19 August 2022 [Page 72] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 enum successful-password-changed { description "The password has been changed successfully"; } enum failed-password-changed{ description "The attempt to change password has failed"; } enum lock { description "The user has been locked. A locked user cannot login."; } enum unlock { description "The user has been unlocked."; } } description "User activities, e.g., Successful User Login, Failed Login attempts, User Logout, Successful User Password Change, Failed User Password Change, User Lockout, User Unlocking, and Unknown."; } } } case i2nsf-nsf-log-dpi { if-feature "i2nsf-nsf-log-dpi"; container i2nsf-nsf-log-dpi { description "This notification is sent, if there is a new DPI event in the NSF log."; leaf attack-type { type dpi-type; description "The type of the DPI"; } uses characteristics; uses i2nsf-nsf-counters-type-content; uses common-monitoring-data; } } } } notification i2nsf-nsf-event { description "Notification for I2NSF NSF Event. This notification is Jeong, et al. Expires 19 August 2022 [Page 73] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 used for a specific NSF that supported such feature."; uses language; choice sub-event-type { description "This choice must be augmented with cases for each allowed sub-event. Only 1 sub-event will be instantiated in each i2nsf-event message. Each case is expected to define one container with all the sub-event fields."; case i2nsf-nsf-detection-ddos { if-feature "i2nsf-nsf-detection-ddos"; container i2nsf-nsf-detection-ddos { description "This notification is sent, when a specific flood type is detected."; leaf attack-type { type identityref { base ddos-type; } description "Any one of Syn flood, ACK flood, SYN-ACK flood, FIN/RST flood, TCP Connection flood, UDP flood, ICMP (i.e., ICMPv4 or ICMPv6) flood, HTTP flood, HTTPS flood, DNS query flood, DNS reply flood, SIP flood, etc."; } leaf start-time { type yang:date-and-time; mandatory true; description "The time stamp indicating when the attack started"; } leaf end-time { type yang:date-and-time; description "The time stamp indicating when the attack ended. If the attack is still undergoing when sending out the notification, this field can be empty."; } leaf-list attack-src-ip { type inet:ip-address-no-zone; description "The source IPv4 (or IPv6) addresses of attack traffic. It can hold multiple IPv4 (or IPv6) addresses."; } leaf-list attack-dst-ip { Jeong, et al. Expires 19 August 2022 [Page 74] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 type inet:ip-address-no-zone; description "The destination IPv4 (or IPv6) addresses of attack traffic. It can hold multiple IPv4 (or IPv6) addresses."; } leaf-list attack-src-port { type inet:port-number; description "The transport layer source ports of the DDoS attack"; } leaf-list attack-dst-port { type inet:port-number; description "The transport layer destination ports of the DDoS attack"; } leaf rule-name { type leafref { path "/nsfintf:i2nsf-security-policy" +"/nsfintf:rules/nsfintf:name"; } mandatory true; description "The name of the I2NSF Policy Rule being triggered"; } uses attack-rates; uses log-action; uses characteristics; uses common-monitoring-data; } } case i2nsf-nsf-detection-virus { if-feature "i2nsf-nsf-detection-virus"; container i2nsf-nsf-detection-virus { description "This notification is sent, when a virus is detected."; uses i2nsf-nsf-event-type-content-extend; leaf virus-name { type string; description "The name of the detected virus"; } leaf virus-type { type identityref { base virus-type; Jeong, et al. Expires 19 August 2022 [Page 75] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } description "The virus type of the detected virus"; } leaf host { type union { type string; type inet:ip-address-no-zone; } description "The name or IP address of the host/device. This is used to identify the host/device that is infected by the virus. If the given name is not an IP address, the name can be an arbitrary string including a FQDN (Fully Qualified Domain Name). The name MUST be unique in the scope of management domain for identifying the device that has been infected with a virus."; } leaf file-type { type string; description "The type of file virus code is found in (if applicable)."; reference "IANA Website: Media Types"; } leaf file-name { type string; description "The name of file virus code is found in (if applicable)."; } leaf os { type string; description "The operating system of the device."; } uses log-action; uses characteristics; uses common-monitoring-data; } } case i2nsf-nsf-detection-intrusion { if-feature "i2nsf-nsf-detection-intrusion"; container i2nsf-nsf-detection-intrusion { description "This notification is sent, when an intrusion event is detected."; Jeong, et al. Expires 19 August 2022 [Page 76] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 uses i2nsf-nsf-event-type-content-extend; leaf protocol { type identityref { base transport-protocol; } description "The transport protocol type for nsf-detection-intrusion notification"; } leaf app { type identityref { base application-protocol; } description "The employed application layer protocol"; } leaf attack-type { type identityref { base intrusion-attack-type; } description "The sub attack type for intrusion attack"; } uses log-action; uses attack-rates; uses characteristics; uses common-monitoring-data; } } case i2nsf-nsf-detection-web-attack { if-feature "i2nsf-nsf-detection-web-attack"; container i2nsf-nsf-detection-web-attack { description "This notification is sent, when an attack event is detected."; uses i2nsf-nsf-event-type-content-extend; leaf attack-type { type identityref { base web-attack-type; } description "Concrete web attack type, e.g., SQL injection, command injection, XSS, and CSRF."; } leaf req-method { type identityref { base req-method; } Jeong, et al. Expires 19 August 2022 [Page 77] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 description "The HTTP method of the request, e.g., PUT or GET."; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Request Methods"; } leaf req-target { type string; description "The HTTP Request Target. This field can be filled in the format of origin-form, absolute-form, authority-form, or asterisk-form"; reference "draft-ietf-httpbis-messaging-19: HTTP/1.1 - Request Target"; } leaf-list filtering-type { type identityref { base filter-type; } description "URL filtering type, e.g., deny-list, allow-list, and Unknown"; } leaf req-user-agent { type string; description "The HTTP User-Agent header field of the request"; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - User Agent"; } leaf cookie { type string; description "The HTTP Cookie header field of the request from the user agent."; reference "RFC 6265: HTTP State Management Mechanism - Cookie"; } leaf req-host { type string; description "The HTTP Host header field of the request"; reference "draft-ietf-httpbis-semantics-19: HTTP Semantics - Host"; } leaf response-code { Jeong, et al. Expires 19 August 2022 [Page 78] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 type string; description "The HTTP Response status code"; reference "IANA Website: Hypertext Transfer Protocol (HTTP) Status Code Registry"; } uses characteristics; uses log-action; uses common-monitoring-data; } } case i2nsf-nsf-detection-voip-vocn { if-feature "i2nsf-nsf-detection-voip-vocn"; container i2nsf-nsf-detection-voip-vocn { description "This notification is sent, when a VoIP/VoCN violation is detected."; uses i2nsf-nsf-event-type-content-extend; leaf-list source-voice-id { type string; description "The detected source voice ID for VoIP and VoCN that violates the security policy."; } leaf-list destination-voice-id { type string; description "The detected destination voice ID for VoIP and VoCN that violates the security policy."; } leaf-list user-agent { type string; description "The detected user-agent for VoIP and VoCN that violates the security policy."; } uses common-monitoring-data; } } } } /* * Data nodes */ container i2nsf-counters { config false; description Jeong, et al. Expires 19 August 2022 [Page 79] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 "The state data representing continuous value changes of information elements that occur very frequently. The value should be calculated from the start of the service of the NSF."; uses language; list system-interface { key interface-name; description "Interface counters provide the visibility of traffic into and out of an NSF, and bandwidth usage."; uses characteristics; uses i2nsf-system-counter-type-content; uses common-monitoring-data; uses timestamp; } list nsf-firewall { key policy-name; description "Firewall counters provide the visibility of traffic signatures, bandwidth usage, and how the configured security and bandwidth policies have been applied."; uses characteristics; uses i2nsf-nsf-counters-type-content; uses traffic-rates; uses common-monitoring-data; uses timestamp; } list nsf-policy-hits { key policy-name; description "Policy hit counters record the number of hits that traffic packets match a security policy. It can check if policy configurations are correct or not."; uses characteristics; uses i2nsf-nsf-counters-type-content; uses common-monitoring-data; leaf discontinuity-time { type yang:date-and-time; mandatory true; description "The time on the most recent occasion at which any one or more of the counters suffered a discontinuity. If no such discontinuities have occurred since the last re-initialization of the local management subsystem, then this node contains the time the local management subsystem was re-initialized."; Jeong, et al. Expires 19 August 2022 [Page 80] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 } leaf hit-times { type yang:counter64; description "The number of times that the security policy matches the specified traffic."; } uses timestamp; } } container i2nsf-monitoring-configuration { description "The container for configuring I2NSF monitoring."; container i2nsf-system-detection-alarm { description "The container for configuring I2NSF system-detection-alarm notification"; uses enable-notification; list system-alarm { key alarm-type; description "Configuration for system alarm (i.e., CPU, Memory, and Disk Usage)"; leaf alarm-type { type enumeration { enum cpu { description "To configure the CPU usage threshold to trigger the cpu-alarm"; } enum memory { description "To configure the Memory usage threshold to trigger the memory-alarm"; } enum disk { description "To configure the Disk (storage) usage threshold to trigger the disk-alarm"; } } description "Type of alarm to be configured. The three alarm-types defined here are used to configure the threshold of the monitoring notification. The threshold is used to determine when the notification should be sent. The other two alarms defined in the module (i.e., Jeong, et al. Expires 19 August 2022 [Page 81] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 hardware-alarm and interface-alarm) do not use any threshold value to create a notification. These alarms detect a failure or a change of state to create a notification."; } leaf threshold { type uint8 { range "1..100"; } units "percent"; description "The configuration for threshold percentage to trigger the alarm. The alarm will be triggered if the usage is exceeded the threshold."; } uses dampening; } } container i2nsf-system-detection-event { description "The container for configuring I2NSF system-detection-event notification"; uses enable-notification; uses dampening; } container i2nsf-traffic-flows { description "The container for configuring I2NSF traffic-flows notification"; uses dampening; uses enable-notification; } container i2nsf-nsf-detection-ddos { if-feature "i2nsf-nsf-detection-ddos"; description "The container for configuring I2NSF nsf-detection-ddos notification"; uses enable-notification; uses dampening; } container i2nsf-nsf-detection-session-table { description "The container for configuring I2NSF nsf-detection-session- table notification"; uses enable-notification; uses dampening; } container i2nsf-nsf-detection-intrusion { Jeong, et al. Expires 19 August 2022 [Page 82] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 if-feature "i2nsf-nsf-detection-intrusion"; description "The container for configuring I2NSF nsf-detection-intrusion notification"; uses enable-notification; uses dampening; } container i2nsf-nsf-detection-web-attack { if-feature "i2nsf-nsf-detection-web-attack"; description "The container for configuring I2NSF nsf-detection-web-attack notification"; uses enable-notification; uses dampening; } container i2nsf-nsf-system-access-log { description "The container for configuring I2NSF system-access-log notification"; uses enable-notification; uses dampening; } container i2nsf-system-res-util-log { description "The container for configuring I2NSF system-res-util-log notification"; uses enable-notification; uses dampening; } container i2nsf-system-user-activity-log { description "The container for configuring I2NSF system-user-activity-log notification"; uses enable-notification; uses dampening; } container i2nsf-nsf-log-dpi { if-feature "i2nsf-nsf-log-dpi"; description "The container for configuring I2NSF nsf-log-dpi notification"; uses enable-notification; uses dampening; } container i2nsf-counter { description "This is used to configure the counters for monitoring an NSF"; Jeong, et al. Expires 19 August 2022 [Page 83] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 leaf period { type uint16; units "minutes"; default 0; description "The configuration for the period interval of reporting the counter. If 0, then the counter period is disabled. If value is not 0, then the counter will be reported following the period value."; } } } } Figure 2: Data Model of Monitoring 9. I2NSF Event Stream This section discusses the NETCONF event stream for an I2NSF NSF Monitoring subscription. The YANG module in this document supports "ietf-subscribed-notifications" YANG module [RFC8639] for subscription. The reserved event stream name for this document is "I2NSF-Monitoring". The NETCONF Server (e.g., an NSF) MUST support "I2NSF-Monitoring" event stream for an NSF data collector (e.g., Security Controller). The "I2NSF-Monitoring" event stream contains all I2NSF events described in this document. The following XML example shows the capabilities of the event streams generated by an NSF (e.g., "NETCONF" and "I2NSF-Monitoring" event streams) for the subscription of an NSF data collector. Refer to [RFC5277] for more detailed explanation of Event Streams. The XML examples in this document follow the line breaks as per [RFC8792]. Jeong, et al. Expires 19 August 2022 [Page 84] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 NETCONF Default NETCONF Event Stream false I2NSF-Monitoring I2NSF Monitoring Event Stream true 2021-04-29T09:37:39+00:00 Figure 3: Example of NETCONF Server supporting I2NSF-Monitoring Event Stream 10. XML Examples for I2NSF NSF Monitoring This section shows XML examples of I2NSF NSF Monitoring data delivered via Monitoring Interface from an NSF. In order for the XML data to be used correctly, the prefix (i.e., the characters before the colon or 'nsfmi' in the example) in the content of the element that uses the "identityref" type (e.g., /i2nsf-event/i2nsf-system- detection-alarm/alarm-category/) in the YANG module described in this document MUST be the same as the namespace prefix (i.e., 'nsfmi' in the example) for urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf- monitoring. Therefore, XML software MUST be chosen that makes the namespace prefix information available. 10.1. I2NSF System Detection Alarm The following example shows an alarm triggered by Memory Usage on the server; this example XML file is delivered by an NSF to an NSF data collector: Jeong, et al. Expires 19 August 2022 [Page 85] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 2021-04-29T07:43:52.181088+00:00 nsfmi:memory-alarm nsfmi:subscription nsfmi:on-change nsfmi:on-repetition 91 90 Memory Usage Exceeded the Threshold time_based_firewall high Figure 4: Example of I2NSF System Detection Alarm triggered by Memory Usage The XML data above shows: 1. The NSF that sends the information is named "time_based_firewall". 2. The memory usage of the NSF triggered the alarm. 3. The monitoring information is received by subscription method. Jeong, et al. Expires 19 August 2022 [Page 86] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 4. The monitoring information is emitted "on-change". 5. The monitoring information is dampened "on-repetition". 6. The memory usage of the NSF is 91 percent. 7. The memory threshold to trigger the alarm is 90 percent. 8. The severity level of the notification is high. 10.2. I2NSF Interface Counters To get the I2NSF system interface counters information by query, NETCONF Client (e.g., NSF data collector) needs to initiate GET connection with NETCONF Server (e.g., NSF). The following XML file can be used to get the state data and filter the information. Figure 5: XML Example for NETCONF GET with System Interface Filter The following XML file shows the reply from the NETCONF Server (e.g., NSF): Jeong, et al. Expires 19 August 2022 [Page 87] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 2021-04-29T08:43:52.181088+00:00 ens3 nsfmi:query 549050 814956 0 5078 time_based_firewall 2021-04-29T08:43:52.181088+00:00 lo nsfmi:query 48487 48487 0 0 time_based_firewall Figure 6: Example of I2NSF System Interface Counters XML Information Jeong, et al. Expires 19 August 2022 [Page 88] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 11. IANA Considerations This document requests IANA to register the following URI in the "IETF XML Registry" [RFC3688]: URI: urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring Registrant Contact: The IESG. XML: N/A; the requested URI is an XML namespace. This document requests IANA to register the following YANG module in the "YANG Module Names" registry [RFC7950][RFC8525]: name: ietf-i2nsf-nsf-monitoring namespace: urn:ietf:params:xml:ns:yang:ietf-i2nsf-nsf-monitoring prefix: nsfmi reference: RFC XXXX // RFC Ed.: replace XXXX with an actual RFC number and remove // this note. 12. Security Considerations The YANG module described in this document defines a schema for data that is designed to be accessed via network management protocols such as NETCONF [RFC6241] or RESTCONF [RFC8040]. The lowest NETCONF layer is the secure transport layer, and the required secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the required secure transport is TLS [RFC8446]. The NETCONF access control model [RFC8341] provides a means of restricting access by specific NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. All data nodes defined in the YANG module which can be created, modified and deleted (i.e., config true, which is the default) are considered sensitive as they all could potentially impact security monitoring and mitigation activities. Write operations (e.g., edit- config) applied to these data nodes without proper protection could result in missed alarms or incorrect alarms information being returned to the NSF data collector. The following are threats that need to be considered and mitigated: Compromised NSF with valid credentials: It can send falsified Jeong, et al. Expires 19 August 2022 [Page 89] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 information to the NSF data collector to mislead detection or mitigation activities; and/or to hide activity. Currently, there is no in-framework mechanism to mitigate this and it is an issue for all monitoring infrastructures. It is important to keep confidential information from unauthorized persons to mitigate the possibility of compromising the NSF with this information. Compromised NSF data collector with valid credentials: It has visibility to all collected security alarms; the entire detection and mitigation infrastructure may be suspect. It is important to keep confidential information from unauthorized persons to mitigate the possibility of compromising the NSF with this information. Impersonating NSF: This involves a system trying to send false information while imitating an NSF; client authentication would help the NSF data collector to identify this invalid NSF in the "push" model (NSF-to-collector), while the "pull" model (collector-to-NSF) should already be addressed with the authentication. Impersonating NSF data collector: This is a rogue NSF data collector with which a legitimate NSF is tricked into communicating; for "push" model (NSF-to-collector), it is important to have valid credentials, without which it should not work; for "pull" model (collector-to-NSF), mutual authentication should be used to mitigate the threat. In addition, to defend against the DDoS attack caused by a lot of NSFs sending massive notifications to the NSF data collector, the rate limiting or similar mechanisms should be considered in both an NSF and NSF data collector, whether in advance or just in the process of DDoS attack. All of the readable data nodes in this YANG module may be considered sensitive in some network environments. These data nodes represent information consistent with the logging commonly performed in network and security operations. They may reveal the specific configuration of a network; vulnerabilities in specific systems; and the deployed security controls and their relative efficacy in detecting or mitigating an attack. To an attacker, this information could inform how to (further) compromise the network, evade detection, or confirm whether they have been observed by the network operator. Jeong, et al. Expires 19 August 2022 [Page 90] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 Additionally, many of the data nodes in this YANG module such as containers "i2nsf-system-user-activity-log", "i2nsf-system-detection- event", and "i2nsf-nsf-detection-voip-vocn" are privacy sensitive. They may describe specific or aggregate user activity including associating user names with specific IP addresses; or users with specific network usage. 13. Acknowledgments This document is a product by the I2NSF Working Group (WG) including WG Chairs (i.e., Linda Dunbar and Yoav Nir) and Diego Lopez. This document took advantage of the review and comments from the following people: Roman Danyliw, Tim Bray (IANA), Kyle Rose (TSV-ART), Dale R. Worley (Gen-ART), Melinda Shore (SecDir), Valery Smyslov (ART-ART), and Tom Petch. The authors sincerely appreciate their sincere efforts and kind help. This work was supported by Institute of Information & Communications Technology Planning & Evaluation (IITP) grant funded by the Korea MSIT (Ministry of Science and ICT) (R-20160222-002755, Cloud based Security Intelligence Technology Development for the Customized Security Service Provisioning). This work was supported in part by the IITP (2020-0-00395, Standard Development of Blockchain based Network Management Automation Technology). This work was supported in part by the MSIT under the Information Technology Research Center (ITRC) support program (IITP-2021-2017-0-01633) supervised by the IITP. 14. Contributors The following are co-authors of this document: Chaehong Chung - Department of Electronic, Electrical and Computer Engineering, Sungkyunkwan University, 2066 Seobu-ro Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea, Email: darkhong@skku.edu Jinyong (Tim) Kim - Department of Electronic, Electrical and Computer Engineering, Sungkyunkwan University, 2066 Seobu-ro Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea, Email: timkim@skku.edu Dongjin Hong - Department of Electronic, Electrical and Computer Engineering, Sungkyunkwan University, 2066 Seobu-ro Jangan-gu, Suwon, Gyeonggi-do 16419, Republic of Korea, Email: dong.jin@skku.edu Dacheng Zhang - Huawei, Email: dacheng.zhang@huawei.com Yi Wu - Aliababa Group, Email: anren.wy@alibaba-inc.com Jeong, et al. Expires 19 August 2022 [Page 91] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 Rakesh Kumar - Juniper Networks, 1133 Innovation Way, Sunnyvale, CA 94089, USA, Email: rkkumar@juniper.net Anil Lohiya - Juniper Networks, Email: alohiya@juniper.net 15. References 15.1. Normative References [RFC0768] Postel, J., "User Datagram Protocol", STD 6, RFC 768, DOI 10.17487/RFC0768, August 1980, . [RFC0791] Postel, J., "Internet Protocol", STD 5, RFC 791, DOI 10.17487/RFC0791, September 1981, . [RFC0792] Postel, J., "Internet Control Message Protocol", STD 5, RFC 792, DOI 10.17487/RFC0792, September 1981, . [RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, DOI 10.17487/RFC0793, September 1981, . [RFC0854] Postel, J. and J. Reynolds, "Telnet Protocol Specification", STD 8, RFC 854, DOI 10.17487/RFC0854, May 1983, . [RFC0959] Postel, J. and J. Reynolds, "File Transfer Protocol", STD 9, RFC 959, DOI 10.17487/RFC0959, October 1985, . [RFC1939] Myers, J. and M. Rose, "Post Office Protocol - Version 3", STD 53, RFC 1939, DOI 10.17487/RFC1939, May 1996, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC2595] Newman, C., "Using TLS with IMAP, POP3 and ACAP", RFC 2595, DOI 10.17487/RFC2595, June 1999, . Jeong, et al. Expires 19 August 2022 [Page 92] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC3877] Chisholm, S. and D. Romascanu, "Alarm Management Information Base (MIB)", RFC 3877, DOI 10.17487/RFC3877, September 2004, . [RFC4340] Kohler, E., Handley, M., and S. Floyd, "Datagram Congestion Control Protocol (DCCP)", RFC 4340, DOI 10.17487/RFC4340, March 2006, . [RFC4443] Conta, A., Deering, S., and M. Gupta, Ed., "Internet Control Message Protocol (ICMPv6) for the Internet Protocol Version 6 (IPv6) Specification", STD 89, RFC 4443, DOI 10.17487/RFC4443, March 2006, . [RFC5277] Chisholm, S. and H. Trevino, "NETCONF Event Notifications", RFC 5277, DOI 10.17487/RFC5277, July 2008, . [RFC5321] Klensin, J., "Simple Mail Transfer Protocol", RFC 5321, DOI 10.17487/RFC5321, October 2008, . [RFC5646] Phillips, A., Ed. and M. Davis, Ed., "Tags for Identifying Languages", BCP 47, RFC 5646, DOI 10.17487/RFC5646, September 2009, . [RFC6241] Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011, . [RFC6242] Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, June 2011, . [RFC6265] Barth, A., "HTTP State Management Mechanism", RFC 6265, DOI 10.17487/RFC6265, April 2011, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . Jeong, et al. Expires 19 August 2022 [Page 93] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 [RFC7011] Claise, B., Ed., Trammell, B., Ed., and P. Aitken, "Specification of the IP Flow Information Export (IPFIX) Protocol for the Exchange of Flow Information", STD 77, RFC 7011, DOI 10.17487/RFC7011, September 2013, . [RFC7950] Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, August 2016, . [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, . [RFC8200] Deering, S. and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification", STD 86, RFC 8200, DOI 10.17487/RFC8200, July 2017, . [RFC8329] Lopez, D., Lopez, E., Dunbar, L., Strassner, J., and R. Kumar, "Framework for Interface to Network Security Functions", RFC 8329, DOI 10.17487/RFC8329, February 2018, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . [RFC8341] Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, March 2018, . [RFC8342] Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, March 2018, . [RFC8343] Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, March 2018, . Jeong, et al. Expires 19 August 2022 [Page 94] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 [RFC8407] Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, October 2018, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8525] Bierman, A., Bjorklund, M., Schoenwaelder, J., Watsen, K., and R. Wilton, "YANG Library", RFC 8525, DOI 10.17487/RFC8525, March 2019, . [RFC8639] Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, E., and A. Tripathy, "Subscription to YANG Notifications", RFC 8639, DOI 10.17487/RFC8639, September 2019, . [RFC8641] Clemm, A. and E. Voit, "Subscription to YANG Notifications for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641, September 2019, . [RFC9051] Melnikov, A., Ed. and B. Leiba, Ed., "Internet Message Access Protocol (IMAP) - Version 4rev2", RFC 9051, DOI 10.17487/RFC9051, August 2021, . [I-D.ietf-httpbis-http2bis] Thomson, M. and C. Benfield, "HTTP/2", Work in Progress, Internet-Draft, draft-ietf-httpbis-http2bis-07, 24 January 2022, . [I-D.ietf-httpbis-messaging] Fielding, R. T., Nottingham, M., and J. Reschke, "HTTP/1.1", Work in Progress, Internet-Draft, draft-ietf- httpbis-messaging-19, 12 September 2021, . [I-D.ietf-httpbis-semantics] Fielding, R. T., Nottingham, M., and J. Reschke, "HTTP Semantics", Work in Progress, Internet-Draft, draft-ietf- httpbis-semantics-19, 12 September 2021, . Jeong, et al. Expires 19 August 2022 [Page 95] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 [I-D.ietf-i2nsf-capability-data-model] Hares, S., Jeong, J. (., Kim, J. (., Moskowitz, R., and Q. Lin, "I2NSF Capability YANG Data Model", Work in Progress, Internet-Draft, draft-ietf-i2nsf-capability-data-model-26, 10 February 2022, . [I-D.ietf-i2nsf-nsf-facing-interface-dm] Kim, J. (., Jeong, J. (., Park, J., Hares, S., and Q. Lin, "I2NSF Network Security Function-Facing Interface YANG Data Model", Work in Progress, Internet-Draft, draft-ietf- i2nsf-nsf-facing-interface-dm-20, 31 January 2022, . [I-D.ietf-tcpm-rfc793bis] Eddy, W. M., "Transmission Control Protocol (TCP) Specification", Work in Progress, Internet-Draft, draft- ietf-tcpm-rfc793bis-26, 8 February 2022, . [I-D.ietf-tsvwg-rfc4960-bis] Stewart, R. R., Tüxen, M., and K. E. E. Nielsen, "Stream Control Transmission Protocol", Work in Progress, Internet-Draft, draft-ietf-tsvwg-rfc4960-bis-18, 16 January 2022, . 15.2. Informative References [RFC4949] Shirey, R., "Internet Security Glossary, Version 2", FYI 36, RFC 4949, DOI 10.17487/RFC4949, August 2007, . [RFC8792] Watsen, K., Auerswald, E., Farrel, A., and Q. Wu, "Handling Long Lines in Content of Internet-Drafts and RFCs", RFC 8792, DOI 10.17487/RFC8792, June 2020, . [I-D.ietf-i2nsf-consumer-facing-interface-dm] Jeong, J. (., Chung, C., Ahn, T., Kumar, R., and S. Hares, "I2NSF Consumer-Facing Interface YANG Data Model", Work in Progress, Internet-Draft, draft-ietf-i2nsf-consumer- facing-interface-dm-16, 28 January 2022, . Jeong, et al. Expires 19 August 2022 [Page 96] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 [IANA-HTTP-Status-Code] Internet Assigned Numbers Authority (IANA), "Hypertext Transfer Protocol (HTTP) Status Code Registry", September 2018, . [IANA-Media-Types] Internet Assigned Numbers Authority (IANA), "Media Types", August 2021, . Appendix A. Changes from draft-ietf-i2nsf-nsf-monitoring-data-model-14 The following changes are made from draft-ietf-i2nsf-nsf-monitoring- data-model-14: * This version is added to update the references. Authors' Addresses Jaehoon (Paul) Jeong (editor) Department of Computer Science and Engineering Sungkyunkwan University 2066 Seobu-Ro, Jangan-Gu Suwon Gyeonggi-Do 16419 Republic of Korea Phone: +82 31 299 4957 Email: pauljeong@skku.edu URI: http://iotlab.skku.edu/people-jaehoon-jeong.php Patrick Lingga Department of Electrical and Computer Engineering Sungkyunkwan University 2066 Seobu-Ro, Jangan-Gu Suwon Gyeonggi-Do 16419 Republic of Korea Phone: +82 31 299 4957 Email: patricklink@skku.edu Jeong, et al. Expires 19 August 2022 [Page 97] Internet-Draft NSF Monitoring Interface YANG Data Model February 2022 Susan Hares Huawei 7453 Hickory Hill Saline, MI 48176 United States of America Phone: +1-734-604-0332 Email: shares@ndzh.com Liang (Frank) Xia Huawei 101 Software Avenue, Yuhuatai District Nanjing Jiangsu, China Email: Frank.xialiang@huawei.com Henk Birkholz Fraunhofer Institute for Secure Information Technology Rheinstrasse 75 64295 Darmstadt Germany Email: henk.birkholz@sit.fraunhofer.de Jeong, et al. Expires 19 August 2022 [Page 98]