OPSAWG Q. Ma Internet-Draft Q. Wu Intended status: Standards Track Huawei Expires: 11 September 2023 M. Boucadair Orange D. King Lancaster University 10 March 2023 A Policy-based Network Access Control draft-ma-opsawg-ucl-acl-02 Abstract This document defines a YANG module for policy-based network access control, which provides consistent and efficient enforcement of network access control policies based on group identity. Moreover, this document defines a mechanism to ease the maintenance of the mapping between a user-group identifier and a set of IP/MAC addresses to enforce policy-based network access control. Also, the document defines a common schedule YANG module which is designed to be applicable for policy activation based on date and time conditions. In addition, the document defines a RADIUS attribute that is used to communicate the user group identifier as part of identification and authorization information. 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 11 September 2023. Ma, et al. Expires 11 September 2023 [Page 1] Internet-Draft A Policy-based NACL March 2023 Copyright Notice Copyright (c) 2023 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. Conventions and Definitions . . . . . . . . . . . . . . . . . 4 3. Sample Usage . . . . . . . . . . . . . . . . . . . . . . . . 4 4. Policy-based Network Access Control . . . . . . . . . . . . . 5 4.1. Overview . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2. Endpoint Group . . . . . . . . . . . . . . . . . . . . . 8 4.2.1. User Group . . . . . . . . . . . . . . . . . . . . . 8 4.2.2. Device Group . . . . . . . . . . . . . . . . . . . . 9 5. Modules Overview . . . . . . . . . . . . . . . . . . . . . . 9 5.1. The Schedule YANG Module . . . . . . . . . . . . . . . . 9 5.1.1. Examples . . . . . . . . . . . . . . . . . . . . . . 10 5.2. The UCL Extension to the ACL Model . . . . . . . . . . . 13 6. YANG Modules . . . . . . . . . . . . . . . . . . . . . . . . 14 6.1. The "ietf-schedule" YANG Module . . . . . . . . . . . . . 14 6.2. The "ietf-ucl-acl" YANG Module . . . . . . . . . . . . . 21 7. User Access Control Group ID RADIUS Attribute . . . . . . . . 27 8. RADIUS Attributes . . . . . . . . . . . . . . . . . . . . . . 28 9. Security Considerations . . . . . . . . . . . . . . . . . . . 28 9.1. YANG . . . . . . . . . . . . . . . . . . . . . . . . . . 29 9.2. RADIUS . . . . . . . . . . . . . . . . . . . . . . . . . 29 10. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 30 10.1. YANG . . . . . . . . . . . . . . . . . . . . . . . . . . 30 10.2. RADIUS . . . . . . . . . . . . . . . . . . . . . . . . . 30 11. References . . . . . . . . . . . . . . . . . . . . . . . . . 31 11.1. Normative References . . . . . . . . . . . . . . . . . . 31 11.2. Informative References . . . . . . . . . . . . . . . . . 32 Appendix A. Examples Usage . . . . . . . . . . . . . . . . . . . 34 A.1. Configuring the Controller Using Group based ACL . . . . 34 A.2. Configuring a PEP Using Group based ACL . . . . . . . . . 36 A.3. Configuring the PEP Using Address based ACL . . . . . . . 39 Appendix B. Changes between Revisions . . . . . . . . . . . . . 40 Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 41 Ma, et al. Expires 11 September 2023 [Page 2] Internet-Draft A Policy-based NACL March 2023 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 41 1. Introduction With the increased adoption of remote access technologies (e.g., Virtual Private Networks (VPNs)) and Bring Your Own Device (BYOD) policies, enterprises adopted more flexibility related to how, where, and when employees work and collaborate. However, more flexibility comes with increased risks. Enabling office flexibility (e.g., mobility across many access locations) for large-scale employees induces a set of challenges compared to conventional network access management approaches. Examples of such challenges are listed below: * Endpoints do not have a stable IP address. For example, Wireless LAN (WLAN) and VPN clients, as well as back-end Virtual Machine (VM)-based servers, can move; their IP addresses could change as a result. This means that relying on IP/transport fields (e.g., the 5-tuple) is inadequate to ensure consistent and efficient security policy enforcement. IP address-based policies may not be flexible enough to accommodate endpoints with volatile IP addresses. * With the massive adoption of teleworking, there is now a need to apply different security policies to the same set of users under different circumstances (e.g., prevent relaying attacks against a local attachment point to the Enterprise network). For example, network access might be granted based upon criteria such as users' access location, source network reputation, users' role, time-of- day, type of network device used (e.g., corporate issued device versus personal device), device's security posture, etc. This means the network needs to recognize the users' identity and their current context, and map the users to their correct access entitlement to the network. This document defines a common schedule YANG module which is designed to be applicable for policy activation based on date and time conditions. This model is designed with the intent to be reusable in other scheduling contexts. Section 5.2 defines a YANG module for policy-based Network Access Control, which extends the IETF Access Control Lists (ACLs) module defined in [RFC8519]. This module can be used to ensure consistent enforcement of ACL policies based on the group identity. This document defines also a mechanism to establish a mapping between the user-group identifier (ID) and common IP packet headers and other enclosed packet data (e.g., MAC address) to execute the policy-based access control. Ma, et al. Expires 11 September 2023 [Page 3] Internet-Draft A Policy-based NACL March 2023 Last, the document defines a Remote Authentication Dial-in User Service (RADIUS) [RFC2865] attribute that is used to communicate the user group identifier as part of identification and authorization information (Section 7). As the ACL notion has been generalized, not to be device-specific, but also be defined at network/administrative domain levels [I-D.dbb-netmod-acl], the YANG module for policy-based network access control defined in Section 5.2 does not limit how it can be used. The YANG data models in this document conform to the Network Management Datastore Architecture (NMDA) defined in [RFC8342]. 2. Conventions and Definitions 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. The meanings of the symbols in tree diagrams are defined in [RFC8340]. The document uses the terms defined in [RFC8519]. In the current version of the document, the term "endpoint" refers also to a host device or end user that actually connect to a network. While host device here refers to servers, IoTs and other devices owned by the enterprise. 3. Sample Usage Access to some networks (e.g., Enterprise networks) requires to recognize the users' identities no matter how, where, and when they connect to the network resources. Then, the network maps the (connecting) users to their access authorization rights. Such rights are defined following local policies. As discussed in Section 1, because (1) there is a large number of users and (2) the source IP addresses of the same user are in different network segments, deploying a network access control policy for each IP address or network segment is heavy workload. An alternate approach is to configure endpoint groups to classify users and enterprise devices and associate ACLs with endpoint groups so that endpoints in each group can share a group of ACL rules. This approach greatly reduces the workload of the administrators and optimizes the ACL resources. Ma, et al. Expires 11 September 2023 [Page 4] Internet-Draft A Policy-based NACL March 2023 The Network ACLs (NACLs) can be provisioned on devices using specific mechanisms, such as [RFC8519] or [I-D.dbb-netmod-acl]. NACL policies may need to vary over time. For example, companies may restrict (or grant) employees access to specific internal or external resources during work hours, while another policy is adopted during off-hours and weekends. A network administrator may also require to enforce traffic shaping (Section 2.3.3.3 of [RFC2475]) and policing (Section 2.3.3.4 of [RFC2475]) during peak hours in order not to affect other data services. 4. Policy-based Network Access Control 4.1. Overview To provide real-time and consistent enforcement of access control policies, the following functional entities and interfaces are involved: * A Service Orchestrator which coordinates the overall service, including security policies. The service may be connectivity or any other resources that can be hosted and offered by a network. * An SDN Controller which is responsible for maintaining endpoint- group based ACLs and mapping the endpoint-group to the associated attributes information (e.g., IP/MAC address). An SDN Controller also behaves as a Policy Decision Point (PDP) [RFC3198] and pushes the required access control policies to relevant Policy Enforcement Points (PEPs). A PDP is also known as "policy server" [RFC2753]. An SDN Controller may interact with an Authentication, Authorization and Accounting (AAA) server or a Network Access Server (NAS). * A Network Access Server (NAS) entity which handles authentication requests. The NAS interacts with an AAA server to complete user authentication using protocols like RADIUS [RFC2865]. When access is granted, the AAA server provides the group identifier (group ID) to which the user belongs when the user first logs onto the network. A new RADIUS attribute is defined in Section 7 for this purpose. Ma, et al. Expires 11 September 2023 [Page 5] Internet-Draft A Policy-based NACL March 2023 * The AAA server provides a collection of authentication, authorization, and accounting functions. The AAA server is responsible for centralized user information management. The AAA server is preconfigured with user credentials (e.g., user name and password), possible group identities and related user attributes (users may be divided into different groups based on different user attributes). * The Policy Enforcement Point (PEP) [RFC3198] is the central entity which is responsible for enforcing appropriate access control policies. In some cases, a PEP may map incoming packets to their associated source or destination endpoint-group IDs, and acts on the endpoint-group ID based ACL policies, e.g., a NAS as the PEP or a group identifier could be carried in packet header (see Section 6.2.3 in [I-D.ietf-nvo3-encap]). While in other cases, the SDN controller maps the group ID to the related common packet header and delivers IP/MAC address based ACL policies to the required PEPs. Multiple PEPs may be involved in a network. A PEP exposes a NETCONF interface to the SDN Controller [RFC6241]. Figure 1 provides the overall architecture and procedure for policy- based access control management. Ma, et al. Expires 11 September 2023 [Page 6] Internet-Draft A Policy-based NACL March 2023 +------------+ |Orchestrator| +------+-----+ Service | (Step 1) ------------------------------------------+------------- ------------------------------------------+------------- Network | (Step 4) | +-------+ +--------+ +--------+-----------+ |User #1+--+ | AAA | | SDN Controller | +-------+ | | Server +-----+ (PDP) | | +----+---+ +--------+-----------+ | | | | | +---------------+(Step 5) (Step 2) | |(Step 3) | | | | | | | +-+-----------+---------------+------------+ | | +----------------------+ +--------------+| +-------+ +--------+ | Network Access Server| |firewall, etc.|| |User #2+-----------+ | (NAS) | +--------------+| +-------+ | +----------------------+ | | (PEP) | +------------------------------------------+ Figure 1: An Architecture for Group-based Policy Management In reference to Figure 1, the following typical flow is experienced: Step 1: Administrators (or the Orchestrator) configure an SDN controller with network-level ACLs using the YANG module defined in Section 5.2. An example of this is provided in Appendix A.1. Step 2: When a user first logs onto the network, the user is required to be authenticated (e.g., using user name and password) at the NAS. Step 3: The authentication request is then relayed to the AAA server using protocols like RADIUS [RFC2865]. It is assumed that the AAA server has been appropriately configured to store user credentials, e.g., user name, password, group information and other user attributes. If the authentication request succeeds, the user is placed in a user-group which is returned to the network access server as the authentication result (see Section 7). If the authentication fails, the user is not assigned any user- group, which also means that the user has no access; or the user is assigned a special group with very limited access permissions for the network (as a function of the local policy). ACLs are enforced so that flows from that IP address are discarded (or rate-limited) by the network. In some implementations, AAA server can be integrated with an SDN controller. Ma, et al. Expires 11 September 2023 [Page 7] Internet-Draft A Policy-based NACL March 2023 Step 4: Either the AAA server or the NAS notify the SDN controller the mapping between the user-group ID and related common packet header attributes (e.g., IP/MAC address). Step 5: Either group or IP/MAC address based access control policies are maintained on relevant PEPs under the controller's management. Whether the PEP enforces the group or IP/MAC address based ACL is implementation specific. Either type of ACL policies may exist on the PEP. Appendix A.2 and Appendix A.3 elaborate on each case. 4.2. Endpoint Group 4.2.1. User Group The user-group ID is an identifier that represents the collective identity of a group of users. It is determined by a set of predefined policy criteria (e.g., source IP address, geolocation data, time of day, or device certificate). Users may be moved to different user-groups if their composite attributes, environment, and/or local enterprise policy change. A user is authenticated, and classified at the AAA server, and assigned to a user-group. A user's group membership may change as aspects of the user change. For example, if the user-group membership is determined solely by the source IP address, then a given user's user-group ID will change when the user moves to a new IP address that falls outside of the range of addresses of the previous user-group. This document does not make any assumption about how user groups are defined. Such considerations are deployment specific and are out of scope. However, and for illustration purposes, Table 1 shows an example of how user-group definitions may be characterized. User- groups may share several common criteria. That is, user-group criteria are not mutually exclusive. For example, the policy criteria of user-groups R&D Regular and R&D BYOD may share the same set of users that belong to the R&D organization, and differ only in the type of clients (firm-issued clients vs. users' personal clients). Likewise, the same user may be assigned to different user- groups depending on the time of day or the type of day (e.g., weekdays versus weekends), etc. Ma, et al. Expires 11 September 2023 [Page 8] Internet-Draft A Policy-based NACL March 2023 +============+==========+===================================+ | Group Name | Group ID | Group Role | +============+==========+===================================+ | R&D | 10 | R&D employees | +------------+----------+-----------------------------------+ | R&D BYOD | 11 | Personal devices of R&D employees | +------------+----------+-----------------------------------+ | Sales | 20 | Sales employees | +------------+----------+-----------------------------------+ | VIP | 30 | VIP employees | +------------+----------+-----------------------------------+ Table 1: User-Group Example 4.2.2. Device Group The device-group ID is an identifier that represents the collective identity of a group of enterprise end devices. An enterprise device could be an server that hosts applications or software that deliver services to enterprise users. It could also be an enterprise IoT device that serve a limited purpose, e.g., a printer that allows users to scan, print and send emails. Table 2 shows an example of how device-group definitions may be characterized. +================+==========+===========================+ | Group Name | Group ID | Group Type | +================+==========+===========================+ | Workflow | 40 | Workflow resource servers | +----------------+----------+---------------------------+ | R&D Resource | 50 | R&D resource servers | +----------------+----------+---------------------------+ | Sales Resource | 54 | Sales resource servers | +----------------+----------+---------------------------+ Table 2: Device-Group Example Users accessing to enterprise device should be strictly controlled. Matching abstract device group ID instead of specified addresses in ACL polices helps shield the consequences of address change (e.g., back-end Virtual Machine (VM)-based server migration). 5. Modules Overview 5.1. The Schedule YANG Module This module defines a common schedule YANG module. It is inspired from the "period of time" and "recurrence rule" format defined in [RFC5545]. Ma, et al. Expires 11 September 2023 [Page 9] Internet-Draft A Policy-based NACL March 2023 This module is defined as a standalone module rather than as part of the UCL module with the intention that the time/date definition can be reused. Figure 2 provides an overview of the tree structure of the "ietf- schedule" module. module: ietf-schedule grouping period: +-- period-of-time +-- (forms)? +--:(period-explicit) | +-- explicit-start? yang:date-and-time | +-- explicit-end? yang:date-and-time +--:(period-start) +-- start? yang:date-and-time +-- duration? duration grouping recurrence: +-- recurrence +-- freq enumeration +-- (recurrence-bound)? | +--:(until) | | +-- until? union | +--:(count) | +-- count? uint32 +-- interval? uint32 +-- bysecond* uint32 +-- byminute* uint32 +-- byhour* uint32 +-- byday* [weekday] | +-- direction* int32 | +-- weekday? schedule:weekday +-- bymonthday* int32 +-- byyearday* int32 +-- byyearweek* int32 +-- byyearmonth* uint32 +-- bysetpos* int32 +-- wkst? schedule:weekday Figure 2: Schedule Tree Structure 5.1.1. Examples The following subsections provide some examples to illustrate the use of the period and recurrence formats defined as YANG groupings. Only the message body is provided with JSON used for encoding [RFC7951]. Ma, et al. Expires 11 September 2023 [Page 10] Internet-Draft A Policy-based NACL March 2023 5.1.1.1. Period of Time The example of a period that starts at 08:00:00 UTC, on January 1, 2023 and ends at 18:00:00 UTC on December 31, 2025 is encoded as follows: { "period-of-time": { "explicit-start": "2023-01-01T08:00:00Z", "explicit-end": "2025-12-01T18:00:00Z" } } An example of a period that starts at 08:00:00 UTC, on January 1, 2023 and lasts 15 days and 5 hours and 20 minutes is encoded as follows: { "period-of-time": { "start": "2023-01-01T08:00:00Z", "duration": "P15DT05:20:00" } } Now, consider the example of a period that starts at 08:00:00 UTC, on January 1, 2023 and lasts 20 weeks: { "period-of-time": { "start": "2023-01-01T08:00:00Z", "duration": "P20W" } } 5.1.1.2. Recurrence Rule The following snippet can be used to indicate a daily recurrent in December: { "recurrence": { "freq": "daily", "byyearmonth": [12] } } The following snippet can be used to indicate 10 occurrences that occur every last Saturday of the month: Ma, et al. Expires 11 September 2023 [Page 11] Internet-Draft A Policy-based NACL March 2023 { "recurrence": { "freq": "monthly", "count": 10, "byday": [ { "direction": [-1], "weekday": "saturday" } ] } } The following indicates the example of a recurrence that occurs on the last workday of the month until December 25, 2023: { "recurrence": { "freq": "monthly", "until": "2023-12-25", "byday": [ { "weekday": "monday" }, { "weekday": "tuesday" }, { "weekday": "wednesday" }, { "weekday": "thursday" }, { "weekday": "friday" } ], "bysetpos": [-1] } } Every other week on Tuesday and Sunday, the week starts from Monday: { "recurrence": { "freq": "weekly", "interval": 2, "byday": [ { "weekday": "tuesday" }, { "weekday": "sunday" } ], "wkst": "monday" } } Ma, et al. Expires 11 September 2023 [Page 12] Internet-Draft A Policy-based NACL March 2023 5.2. The UCL Extension to the ACL Model Figure 3 provides the tree structure of the "ietf-ucl-acl" module. module: ietf-ucl-acl augment /acl:acls/acl:acl: +--rw endpoint-groups +--rw endpoint-group* [group-id] +--rw group-id uint32 +--rw (group-type)? +--:(user-group) | +--rw user-group | +--rw role? string +--:(device-group) +--rw device-group +--rw device-type? string augment /acl:acls/acl:acl/acl:aces/acl:ace/acl:matches: +--rw endpoint-group {match-on-group}? +--rw source-group-id? leafref +--rw destination-group-id? leafref augment /acl:acls/acl:acl/acl:aces/acl:ace: +--rw time-range {time-condition}? +--rw (time-range-type)? +--:(periodic-range) | +--rw recurrence | +--rw freq enumeration | +--rw (recurrence-bound)? | | +--:(until) | | | +--rw until? union | | +--:(count) | | +--rw count? uint32 | +--rw interval? uint32 | +--rw bysecond* uint32 | +--rw byminute* uint32 | +--rw byhour* uint32 | +--rw byday* [weekday] | | +--rw direction* int32 | | +--rw weekday schedule:weekday | +--rw bymonthday* int32 | +--rw byyearday* int32 | +--rw byyearweek* int32 | +--rw byyearmonth* uint32 | +--rw bysetpos* int32 | +--rw wkst* schedule:weekday | +--rw duration? schedule:duration +--:(absolute-range) +--rw period-of-time Ma, et al. Expires 11 September 2023 [Page 13] Internet-Draft A Policy-based NACL March 2023 +--rw (forms)? +--:(period-explicit) | +--rw explicit-start? yang:date-and-time | +--rw explicit-end? yang:date-and-time +--:(period-start) +--rw start? yang:date-and-time +--rw duration? duration Figure 3: UCL Extension This module specifies an extension to the IETF ACL model [RFC8519] such that the UCL group index can be referenced by augmenting the "match" data node. 6. YANG Modules 6.1. The "ietf-schedule" YANG Module This module imports types defined in [I-D.ietf-netmod-rfc6991-bis]. file=ietf-schedule@2023-01-19.yang module ietf-schedule { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-schedule"; prefix schedule; import ietf-yang-types { prefix yang; revision-date 2023-01-23; reference "RFC XXXX: Common YANG Data Types"; } organization "IETF OPSAWG Working Group"; contact "WG Web: WG List: "; description "This YANG module defines two groupings for iCalendar (Internet Calendaring and Scheduling Core Object Specification) data types:period of time and recurrence rule, for representing and exchanging calendaring and scheduling information. The YANG module complies with sections 3.3.9 and 3.3.10 in RFC 5545. Future extensions may define more as needed. Copyright (c) 2023 IETF Trust and the persons identified Ma, et al. Expires 11 September 2023 [Page 14] Internet-Draft A Policy-based NACL March 2023 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 Revised 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 2023-01-19 { description "Initial revision."; reference "RFC XXXX: A Policy-based Network Access Control"; } typedef weekday { type enumeration { enum sunday { value 0; description "Sunday of the week."; } enum monday { value 1; description "Monday of the week."; } enum tuesday { value 2; description "Tuesday of the week."; } enum wednesday { value 3; description "Wednesday of the week."; } enum thursday { value 4; description "Thursday of the week."; } enum friday { Ma, et al. Expires 11 September 2023 [Page 15] Internet-Draft A Policy-based NACL March 2023 value 5; description "Friday of the week."; } enum saturday { value 6; description "Saturday of the week."; } } description "Seven days of the week."; } typedef duration { type string { pattern '((\+)?|\-)P((([0-9]+)D)?(T(0[0-9]|1[0-9]|2[0-3])' + ':[0-5][0-9]:[0-5][0-9]))|P([0-9]+)W'; } description "Duration of the time. The format can represent nominal durations (weeks and days) and accurate durations (hours, minutes, and seconds). Note that this value type doesn't support the 'Y' and 'M' designators to specify durations in terms of years and months. Negative durations are typically used to schedule an alarm to trigger before an associated time."; reference "RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)"; } grouping period { description "This grouping is defined for period of time property."; reference "RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)"; container period-of-time { description "This container is defined to identify period values that contain a precise period of time."; choice forms { description "Two forms of period of time."; case period-explicit { description "A period of time is identified by its start and its Ma, et al. Expires 11 September 2023 [Page 16] Internet-Draft A Policy-based NACL March 2023 end."; leaf explicit-start { type yang:date-and-time; description "Period start time."; } leaf explicit-end { type yang:date-and-time; description "Period end time."; } } case period-start { description "A period of time is defined by a start and a positive duration of time."; leaf start { type yang:date-and-time; description "Period start time."; } leaf duration { type duration { pattern 'P((([0-9]+)D)?(T(0[0-9]|1[0-9]|2[0-3])' + ':[0-5][0-9]:[0-5][0-9]))|P([0-9]+)W'; } description "A positive duration of the time."; } } } } } grouping recurrence { description "This grouping is defined to identify properties that contain a recurrence rule specification"; reference "RFC 5545: Internet Calendaring and Scheduling Core Object Specification (iCalendar)"; container recurrence { description "Recurrence rule definition."; leaf freq { type enumeration { enum secondly { value 1; Ma, et al. Expires 11 September 2023 [Page 17] Internet-Draft A Policy-based NACL March 2023 description "Repeating events based on an interval of a second or more."; } enum minutely { value 2; description "Repeating events based on an interval of a minute or more."; } enum hourly { value 3; description "Repeating events based on an interval of an hour or more."; } enum daily { value 4; description "Repeating events based on an interval of a day or more."; } enum weekly { value 5; description "Repeating events based on an interval of a week or more."; } enum monthly { value 6; description "Repeating events based on an interval of a month or more."; } enum yearly { value 7; description "Repeating events based on an interval of a year or more."; } } mandatory true; description "This parameter is defined to identify the type of recurrence rule."; } choice recurrence-bound { description Ma, et al. Expires 11 September 2023 [Page 18] Internet-Draft A Policy-based NACL March 2023 "Modes to bound the recurrence rule. If no choice is indicated, the recurrence rule is considered to repeat forever."; case until { description "This case defines a way that bounds the recurrence rule in an inclusive manner."; leaf until { type union { type yang:date-no-zone; type yang:date-and-time; } description "This parameter specifies a date-no-zone or date-time value to bounds the recurrence. The specified value becomes the last instance of the recurrence."; } } case count { description "This case defines the number of occurrences at which to range-bound the recurrence."; leaf count { type uint32; description "The positive number of occurrences at which to range-bound the recurrence."; } } } leaf interval { type uint32; default "1"; description "A positive integer representing at which intervals the recurrence rule repeats. The default value is '1', meaning every second for a secondly rule, every minute for a minutely rule, every hour for an hourly rule, every day for a daily rule, every week for a weekly rule, every month for a monthly rule, and every year for a yearly rule."; } leaf-list bysecond { type uint32 { range "0..60"; } description Ma, et al. Expires 11 September 2023 [Page 19] Internet-Draft A Policy-based NACL March 2023 "A list of seconds within a minute."; } leaf-list byminute { type uint32 { range "0..59"; } description "A list of minutes within an hour."; } leaf-list byhour { type uint32 { range "0..23"; } description "Specify a list of hours of the day."; } list byday { key "weekday"; description "Specify a list of days of the week."; leaf-list direction { when '(enum-value(../../freq) = 6) or ' + '(enum-value(../../freq) = 7) and not(../../byyearweek)'; type int32 { range "-53..-1|1..53"; } description "When specified, it indicates the nth occurrence of a specific day within the MONTHLY or YEARLY 'RRULE'. For example, within a MONTHLY rule, +1 monday represents the first monday within the month, whereas -1 monday represents the last monday of the month."; } leaf weekday { type schedule:weekday; description "Corresponding to seven days of the week."; } } leaf-list bymonthday { type int32 { range "-31..-1|1..31"; } description "Specifies a list of days of the month."; } leaf-list byyearday { Ma, et al. Expires 11 September 2023 [Page 20] Internet-Draft A Policy-based NACL March 2023 type int32 { range "-366..-1|1..366"; } description "Specifies a list of days of the year."; } leaf-list byyearweek { when 'enum-value(../freq)=7'; type int32 { range "-53..-1|1..53"; } description "Specifies a list of weeks of the year."; } leaf-list byyearmonth { type uint32 { range "1..12"; } description "Specifies a list of months of the year."; } leaf-list bysetpos { type int32 { range "-366..-1|1..366"; } description "Specifies a list of values that corresponds to the nth occurrence within the set of recurrence instances specified by the rule. It must only be used in conjunction with another byXXX rule part."; } leaf wkst { type schedule:weekday; default "monday"; description "Specifies the day on which the workweek starts."; } } } } 6.2. The "ietf-ucl-acl" YANG Module This module imports types defined in [RFC6991], [RFC8194], and [RFC8519]. Ma, et al. Expires 11 September 2023 [Page 21] Internet-Draft A Policy-based NACL March 2023 file=ietf-ucl-acl@2023-01-19.yang module ietf-ucl-acl { yang-version 1.1; namespace "urn:ietf:params:xml:ns:yang:ietf-ucl-acl"; prefix uacl; import ietf-access-control-list { prefix acl; reference "RFC 8519: YANG Data Model for Network Access Control Lists (ACLs)"; } import ietf-schedule { prefix schedule; reference "RFC XXXX: A Policy-based Network Access Control"; } organization "IETF OPSWG Working Group"; contact "WG Web: WG List: "; description "This YANG module augments the IETF access control lists(ACLs) module and is meant to ensure consistent enforcement of ACL policies based on the group identity. Copyright (c) 2023 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 Revised 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 2023-01-19 { description "Initial revision."; reference "RFC XXXX: A Policy-based Network Access Control"; Ma, et al. Expires 11 September 2023 [Page 22] Internet-Draft A Policy-based NACL March 2023 } identity group-acl-type { if-feature "group"; base acl:acl-base; description "An ACL that matches based on an endpoint group identity, which can represent the collective identity of a group of authenticated users or enterprise end devices. An endpoint group identity may be carried in the outer/inner packet header(e.g., via NVO3 encapsulation), but may not correspond to any field in the packet header."; } identity mixed-ipv4-group-type { if-feature "mixed-ipv4-group"; base acl:ipv4-acl-type; base uacl:group-acl-type; description "An ACL that contains a mix of entries that match on fields in IPv4 headers and endpoint group identities, which can represent the collective identity of a group of authenticated users or enterprise end devices. Matching on Layer 4 header fields may also exist in the ACEs."; } identity mixed-ipv6-group-type { if-feature "mixed-ipv6-group"; base acl:ipv6-acl-type; base uacl:group-acl-type; description "An ACL that contains a mix of entries that match on fields in IPv6 headers and endpoint group identities, which can represent the collective identity of a group of authenticated users or enterprise end devices. Matching on Layer 4 header fields may also exist in the ACEs."; } identity mixed-ipv4-ipv6-group-type { if-feature "mixed-ipv4-ipv6-group"; base acl:ipv4-acl-type; base acl:ipv6-acl-type; base uacl:group-acl-type; description "An ACL that contains a mix of entries that match on fields in IPv4 headers, IPv6 headers and endpoint group identities, which can represent the collective identity of a group of authenticated users or enterprise end devices. Matching on Layer 4 header fields may also exist in the ACEs."; } feature match-on-group { Ma, et al. Expires 11 September 2023 [Page 23] Internet-Draft A Policy-based NACL March 2023 description "The device can support matching on endpoint groups."; } feature group { if-feature "uacl:match-on-group"; description "Plain group ACL supported."; } feature mixed-ipv4-group { if-feature "acl:match-on-ipv4 and uacl:match-on-group"; description "IPv4 and group ACL combinations supported."; } feature mixed-ipv6-group { if-feature "acl:match-on-ipv6 and uacl:match-on-group"; description "IPv6 and group ACL combinations supported."; } feature mixed-ipv4-ipv6-group { if-feature "acl:match-on-ipv4 and acl:match-on-ipv6 and " + " uacl:match-on-group"; description "IPv4, IPv6 and group ACL combinations supported."; } feature time-condition { description "The device can support a time condition based ACL policy enforcement."; } augment "/acl:acls/acl:acl" { description "add a new container to store endpoint group information."; container endpoint-groups { description "Container definition for the endpoint group."; list endpoint-group { key "group-id"; description "Definition of the endpoint group list."; leaf group-id { type uint32 { range "0..4294967294"; } description "The endpoint group ID that uniquely identifies an endpoint group."; Ma, et al. Expires 11 September 2023 [Page 24] Internet-Draft A Policy-based NACL March 2023 } choice group-type { description "Choice of each different type of endpoint."; case user-group { description "The employee that actually connects to the network."; container user-group { description "Defines the user-group container."; leaf role { type string; description "The common role of this user-group."; } } } case device-group { description "The static resources in a network, such as a specific application."; container device-group { description "Defines the device-group container."; leaf device-type { type string; description "The type of the static resource."; } } } } } } } augment "/acl:acls/acl:acl/acl:aces/acl:ace/acl:matches" { description "Add another choice to allow ace match based on endpoint group id."; container endpoint-group { when "derived-from-or-self(/acl:acls/acl:acl/acl:type, " + "'uacl:group-acl-type')"; if-feature "match-on-group"; description "Add new match types."; leaf source-group-id { type leafref { Ma, et al. Expires 11 September 2023 [Page 25] Internet-Draft A Policy-based NACL March 2023 path "../../../../../endpoint-groups/endpoint-group/"+ "group-id"; } description "The matched source endpoint group ID."; } leaf destination-group-id { type leafref { path "../../../../../endpoint-groups/endpoint-group/"+ "group-id"; } description "The matched destination endpoint group ID."; } } } augment "/acl:acls/acl:acl/acl:aces/acl:ace" { if-feature "time-condition"; description "Add a new parameter to the Access Control Entry (ACE)."; container time-range { description "This container defines when the access control entry rules are in effect. If it is not configured, the access control entry is immediately and always in effect."; choice time-range-type { description "Choice based on the type of the time range."; case periodic-range { description "A periodic range of time to take effect."; uses schedule:recurrence { augment recurrence { description "Add a parameter to specify the duration of each recurrence trigger."; leaf duration { type schedule:duration { pattern '((\+)?|\-)PT(0[0-9]|1[0-9]|2[0-3]):' + '[0-5][0-9]:[0-5][0-9]'; } description "A duration of time in terms of days when policies are activated in each occurrence."; } Ma, et al. Expires 11 September 2023 [Page 26] Internet-Draft A Policy-based NACL March 2023 } } } case absolute-range { description "A single precise period of time to take effect."; uses schedule:period; } } } } } 7. User Access Control Group ID RADIUS Attribute The User-Access-Group-ID RADIUS attribute and its embedded TLVs are defined with globally unique names. The definition of the attribute follows the guidelines in Section 2.7.1 of [RFC6929]. This attribute is used to indicate the user-group ID to be used by the NAS. When the User-Access-Group-ID RADIUS attribute is present in the RADIUS Access-Accept, the system applies the related access control to the users after it authenticates. The value fields of the Attribute are encoded in clear and not encrypted as, for example, Tunnel- Password Attribute [RFC2868]. The User-Access-Group-ID Attribute is of type "string" as defined in Section 3.5 of [RFC8044]. The User-Access-Group-ID Attribute MAY appear in a RADIUS Access- Accept packet. It MAY also appear in a RADIUS Access-Request packet as a hint to the RADIUS server to indicate a preference. However, the server is not required to honor such a preference. The User-Access-Group-ID Attribute MAY appear in a RADIUS CoA-Request packet. The User-Access-Group-ID Attribute MAY appear in a RADIUS Accounting- Request packet. The User-Access-Group-ID Attribute MUST NOT appear in any other RADIUS packet. The User-Access-Group-ID Attribute is structured as follows: Ma, et al. Expires 11 September 2023 [Page 27] Internet-Draft A Policy-based NACL March 2023 Type 241 Length This field indicates the total length, in octets, of all fields of this attribute, including the Type, Length, Extended-Type, and the "Value". Extended-Type TBA1 Value This field contains the user group ID. The User-Access-Group-ID Attribute is associated with the following identifier: 241.TBA1. 8. RADIUS Attributes The following table provides a guide as what type of RADIUS packets that may contain User-Access-Group-ID Attribute, and in what quantity. Access- Access- Access- Challenge Acct. # Attribute Request Accept Reject Request 0+ 0+ 0 0 0+ 241.TBA1 User-Access-Group-ID CoA-Request CoA-ACK CoA-NACK # Attribute 0+ 0 0 241.TBA2 User-Access-Group-ID The following table defines the meaning of the above table entries: 0 This attribute MUST NOT be present in packet. 0+ Zero or more instances of this attribute MAY be present in packet. 9. Security Considerations Ma, et al. Expires 11 September 2023 [Page 28] Internet-Draft A Policy-based NACL March 2023 9.1. YANG The YANG modules specified in this document defines 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 mandatory-to-implement secure transport is Secure Shell (SSH) [RFC6242]. The lowest RESTCONF layer is HTTPS, and the mandatory-to-implement secure transport is TLS [RFC8446]. The Network Configuration Access Control Model (NACM) [RFC8341] provides the means to restrict access for particular NETCONF or RESTCONF users to a preconfigured subset of all available NETCONF or RESTCONF protocol operations and content. The "ietf-schedule" module defines a set of types and groupings. These nodes are intended to be reused by other YANG modules. The module by itself does not expose any data nodes that are writable, data nodes that contain read-only state, or RPCs. As such, there are no additional security issues related to the "ietf- schedule" module that need to be considered. There are a number of data nodes defined in the "ietf-ucl-acl" YANG module that are writable, creatable, and deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations to these data nodes could have a negative effect on network and security operations. * TBC * TBC Some of the readable data nodes in the "ietf-ucl-acl" YANG module may be considered sensitive or vulnerable in some network environments. It is thus important to control read access (e.g., via get, get-config, or notification) to these data nodes. These are the subtrees and data nodes and their sensitivity/vulnerability: * * 9.2. RADIUS RADIUS-related security considerations are discussed in [RFC2865]. Ma, et al. Expires 11 September 2023 [Page 29] Internet-Draft A Policy-based NACL March 2023 This document targets deployments where a trusted relationship is in place between the RADIUS client and server with communication optionally secured by IPsec or Transport Layer Security (TLS) [RFC6614]. 10. IANA Considerations 10.1. YANG This document registers the following URIs in the "IETF XML Registry" [RFC3688]. URI: urn:ietf:params:xml:ns:yang:ietf-schedule Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. URI: urn:ietf:params:xml:ns:yang:ietf-ucl-acl Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace. This document registers the following YANG modules in the "YANG Module Names" registry [RFC6020]. name: ietf-schedule namespace: urn:ietf:params:xml:ns:yang:ietf-schedule prefix: schedule maintained by IANA: N reference: RFC XXXX name: ietf-ucl-acl namespace: urn:ietf:params:xml:ns:yang:ietf-ucl-acl prefix: uacl maintained by IANA: N reference: RFC XXXX 10.2. RADIUS This document requests IANA to assign a new RADIUS attribute types from the IANA registry "Radius Attribute Types" [RADIUS-Types]: +==========+======================+===========+===============+ | Value | Description | Data Type | Reference | +==========+======================+===========+===============+ | 241.TBA1 | User-Access-Group-ID | string | This-Document | +----------+----------------------+-----------+---------------+ Table 3: RADIUS Attribute Ma, et al. Expires 11 September 2023 [Page 30] Internet-Draft A Policy-based NACL March 2023 11. References 11.1. Normative References [I-D.ietf-netmod-rfc6991-bis] Schönwälder, J., "Common YANG Data Types", Work in Progress, Internet-Draft, draft-ietf-netmod-rfc6991-bis- 15, 23 January 2023, . [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, . [RFC2865] Rigney, C., Willens, S., Rubens, A., and W. Simpson, "Remote Authentication Dial In User Service (RADIUS)", RFC 2865, DOI 10.17487/RFC2865, June 2000, . [RFC3688] Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, January 2004, . [RFC6020] Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, October 2010, . [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, . [RFC6929] DeKok, A. and A. Lior, "Remote Authentication Dial In User Service (RADIUS) Protocol Extensions", RFC 6929, DOI 10.17487/RFC6929, April 2013, . [RFC6991] Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, July 2013, . Ma, et al. Expires 11 September 2023 [Page 31] Internet-Draft A Policy-based NACL March 2023 [RFC8040] Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017, . [RFC8044] DeKok, A., "Data Types in RADIUS", RFC 8044, DOI 10.17487/RFC8044, 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, . [RFC8194] Schoenwaelder, J. and V. Bajpai, "A YANG Data Model for LMAP Measurement Agents", RFC 8194, DOI 10.17487/RFC8194, August 2017, . [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, . [RFC8446] Rescorla, E., "The Transport Layer Security (TLS) Protocol Version 1.3", RFC 8446, DOI 10.17487/RFC8446, August 2018, . [RFC8519] Jethanandani, M., Agarwal, S., Huang, L., and D. Blair, "YANG Data Model for Network Access Control Lists (ACLs)", RFC 8519, DOI 10.17487/RFC8519, March 2019, . 11.2. Informative References [I-D.dbb-netmod-acl] de Dios, O. G., Barguil, S., and M. Boucadair, "Extensions to the Access Control Lists (ACLs) YANG Model", Work in Progress, Internet-Draft, draft-dbb-netmod-acl-03, 24 October 2022, . Ma, et al. Expires 11 September 2023 [Page 32] Internet-Draft A Policy-based NACL March 2023 [I-D.ietf-nvo3-encap] Boutros, S. and D. E. Eastlake, "Network Virtualization Overlays (NVO3) Encapsulation Considerations", Work in Progress, Internet-Draft, draft-ietf-nvo3-encap-09, 7 October 2022, . [I-D.smith-vxlan-group-policy] Smith, M. and L. Kreeger, "VXLAN Group Policy Option", Work in Progress, Internet-Draft, draft-smith-vxlan-group- policy-05, 22 October 2018, . [I-D.yizhou-anima-ip-to-access-control-groups] Li, Y., Shen, L., and Y. Zhou, "Autonomic IP Address To Access Control Group ID Mapping", Work in Progress, Internet-Draft, draft-yizhou-anima-ip-to-access-control- groups-02, 15 November 2021, . [I-D.you-i2nsf-user-group-based-policy] You, J., Zarny, M., Jacquenet, C., Boucadair, M., Li, Y., Strassner, J., and S. Majee, "User-group-based Security Policy for Service Layer", Work in Progress, Internet- Draft, draft-you-i2nsf-user-group-based-policy-02, 8 July 2016, . [NIST-ABAC] Hu, V. C., "Guide to Attribute Based Access Control (ABAC) Definition and Considerations", January 2014, . [RADIUS-Types] IANA, "RADIUS Types", . [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., and W. Weiss, "An Architecture for Differentiated Services", RFC 2475, DOI 10.17487/RFC2475, December 1998, . [RFC2753] Yavatkar, R., Pendarakis, D., and R. Guerin, "A Framework for Policy-based Admission Control", RFC 2753, DOI 10.17487/RFC2753, January 2000, . Ma, et al. Expires 11 September 2023 [Page 33] Internet-Draft A Policy-based NACL March 2023 [RFC2868] Zorn, G., Leifer, D., Rubens, A., Shriver, J., Holdrege, M., and I. Goyret, "RADIUS Attributes for Tunnel Protocol Support", RFC 2868, DOI 10.17487/RFC2868, June 2000, . [RFC3198] Westerinen, A., Schnizlein, J., Strassner, J., Scherling, M., Quinn, B., Herzog, S., Huynh, A., Carlson, M., Perry, J., and S. Waldbusser, "Terminology for Policy-Based Management", RFC 3198, DOI 10.17487/RFC3198, November 2001, . [RFC5545] Desruisseaux, B., Ed., "Internet Calendaring and Scheduling Core Object Specification (iCalendar)", RFC 5545, DOI 10.17487/RFC5545, September 2009, . [RFC6614] Winter, S., McCauley, M., Venaas, S., and K. Wierenga, "Transport Layer Security (TLS) Encryption for RADIUS", RFC 6614, DOI 10.17487/RFC6614, May 2012, . [RFC7951] Lhotka, L., "JSON Encoding of Data Modeled with YANG", RFC 7951, DOI 10.17487/RFC7951, August 2016, . [RFC8340] Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, March 2018, . Appendix A. Examples Usage A.1. Configuring the Controller Using Group based ACL Let's consider an organization that would like to restrict the access of R&D employees that bring personally owned devices (BYOD) into the workplace. The access requirements are as follows: * Permit traffic from R&D BYOD of employees, destined to R&D employees' devices every work day from 8:00 to 18:00. * Deny traffic from R&D BYOD of employees, destined to finance servers located in the enterprise DC network starting at 8:30:00 of January 20, 2023 with an offset of -08:00 from UTC (Pacific Standard Time) and ending at 18:00:00 in Pacific Standard Time on December 31, 2023. Ma, et al. Expires 11 September 2023 [Page 34] Internet-Draft A Policy-based NACL March 2023 The following example illustrates the configuration of the SDN controller using the group-based ACL: sample-group-acl uacl:group-acl-type 20 R&D 22 R&D BYOD 50 finance server rule1 22 20 accept daily 8 Ma, et al. Expires 11 September 2023 [Page 35] Internet-Draft A Policy-based NACL March 2023 monday tuesday wednesday thursday friday PT10:00:00 rule2 22 50 reject 2023-01-20T08:30:00-08:00 2023-12-31T18:00:00-08:00 A.2. Configuring a PEP Using Group based ACL This section illustrates an example to configure a PEP using the group-based ACL. Ma, et al. Expires 11 September 2023 [Page 36] Internet-Draft A Policy-based NACL March 2023 The PEP which enforces group-based ACL may acquire group identities from the AAA server if working as a NAS authenticating both the source endpoint and the destination endpoint users. Another case for a PEP enforcing a group-based ACL is to obtain the group identity of the source endpoint directly from the packet field [I-D.smith-vxlan-group-policy]. This does not intend to be exhaustive. Assume the mapping between device group ID and IP addresses is predefined or acquired via device authentication. The following example shows ACL configurations delivered from the controller to the PEP. This example is consistent with the example presented in Appendix A.1. sample-group-acl uacl:mixed-ipv4-group-type 20 R&D 22 R&D BYOD rule1 22 20 accept Ma, et al. Expires 11 September 2023 [Page 37] Internet-Draft A Policy-based NACL March 2023 daily 8 monday tuesday wednesday thursday friday PT10:00:00 rule2 22 10.1.1.0/24 reject 2023-01-20T08:30:00-08:00 2023-12-31T18:00:00-08:00 Ma, et al. Expires 11 September 2023 [Page 38] Internet-Draft A Policy-based NACL March 2023 A.3. Configuring the PEP Using Address based ACL The section illustrates an example of configuring a PEP using IP address based ACL. IP address based access control policies could be applied to the PEP that may not understand the group information, e.g., firewall. Assume an employee in the R&D department accesses the network wirelessly from a non-corporate laptop using IP address 192.168.1.10. The SDN controller associates the user group to which the employee belongs with the user address according to step 1 to 4 in Section 4.1. Assume the mapping between device group ID and IP addresses is predefined or acquired via device authentication. The following example shows IPv4 address based ACL configurations delivered from the controller to the PEP. This example is consistent with the example presented in Appendix A.1. sample-group-acl ipv4-acl-type rule1 192.168.2.1/24 192.168.1.1/24 accept daily 8 monday Ma, et al. Expires 11 September 2023 [Page 39] Internet-Draft A Policy-based NACL March 2023 tuesday wednesday thursday friday PT10:00:00 rule2 10.1.1.0/24 192.168.1.1/24 reject 2023-01-20T08:30:00-08:00 2023-12-31T18:00:00-08:00 Appendix B. Changes between Revisions v01 - v02 * Add more examples. v00 - v01 * Define a common schedule yang module and reuse in UCL yang module to support time/date-based activation condition. Ma, et al. Expires 11 September 2023 [Page 40] Internet-Draft A Policy-based NACL March 2023 * Either group-based or address-based ACL policies could be enforced at PEP, and allow group-based ACL policies maintained at the network controller. * Optimize the process in section 4.1. * Extend ACL module to support a generalized endpoint-group to cover both end users (e.g., enterprise employees) and enterprise hosts (e.g., IoT devices or servers); * Simplify the definition of group in UCL model with only the most necessary group ID retained. Acknowledgments This work has benefited from the discussions of User-group-based Security Policy over the years. In particular, [I-D.you-i2nsf-user-group-based-policy] and [I-D.yizhou-anima-ip-to-access-control-groups] provide mechanisms to establish a mapping between the IP address/prefix of users and access control group IDs. Jianjie You, Myo Zarny, Christian Jacquenet, Mohamed Boucadair, and Yizhou Li contributed to an earlier version of [I-D.you-i2nsf-user-group-based-policy]. We would like to thank the authors of that draft on modern network access control mechanisms for material that assisted in thinking about this document. The authors would like to thank Joe Clarke, Bill Fenner, Benoit Claise, Rob Wilton, and David Somers-Harris for their valuable comments and great input to this work. Authors' Addresses Qiufang Ma Huawei 101 Software Avenue, Yuhua District Jiangsu 210012 China Email: maqiufang1@huawei.com Ma, et al. Expires 11 September 2023 [Page 41] Internet-Draft A Policy-based NACL March 2023 Qin Wu Huawei 101 Software Avenue, Yuhua District Jiangsu 210012 China Email: bill.wu@huawei.com Mohamed Boucadair Orange 35000 Rennes France Email: mohamed.boucadair@orange.com Daniel King Lancaster University United Kingdom Email: d.king@lancaster.ac.uk Ma, et al. Expires 11 September 2023 [Page 42]