| RTGWG | F. Zheng |
| Internet-Draft | B. Wu |
| Intended status: Standards Track | Huawei |
| Expires: February 25, 2019 | R. Wilton |
| Cisco Systems | |
| X. Ding | |
| August 24, 2018 |
YANG Data Model for ARP
draft-ietf-rtgwg-arp-yang-model-01
This document defines a YANG data model for the management of the Address Resolution Protocol (ARP). It extends the basic ARP functionality contained in the ietf-ip YANG data model, defined in RFC 8344, to provide management of optional ARP features and statistics.
The YANG data model in this document conforms to the Network Management Datastore Architecture defined in RFC 8342.
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 February 25, 2019.
Copyright (c) 2018 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 Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License.
This document defines a YANG [RFC7950] data model for the Address Resolution Protocol [RFC0826] implementation and identification of some common properties within a device. Devices have common properties that need to be configured and monitored in a standard way. This document is intended to present universal ARP protocol configuration and many vendors can implement it.
The data model convers configuration of system parameters of ARP, such as static ARP entries, timeout for dynamic ARP entries, interface ARP, proxy ARP, and so on. It also provides information about running state of ARP implementations.
The YANG modules in this document conform to the Network Management Datastore Architecture (NMDA) [RFC8342].
Editorial Note: (To be removed by RFC Editor)
This draft contains many placeholder values that need to be replaced with finalized values at the time of publication. Please apply the following replacements
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 following terms are defined in [RFC8342] and are not redefined here:
The following terms are defined in [RFC7950] and are not redefined here:
The terminology for describing YANG data models is found in [RFC7950].
Tree diagrams used in this document follow the notation defined in [RFC8340]
This document defines a YANG [RFC7950] configuration data model that may be used to configure the ARP feature running on a system. Data model "ietf-ip" [RFC8344] covers the address mapping functionality. However, this functionality is strictly dependent on IPv4 networks, and many ARP related functionalities are missing, e.g. device global ARP entries and control, configuration related to dynamic ARP learning, proxy ARP, gratuitous ARP, etc.
The data model makes use of the YANG "feature" construct which allows implementations to support only those ARP features that lie within their capabilities. It is intended this model be used by service providers who manipulate devices from different vendors in a standard way.
This model can be used to configure the ARP applications for discovering the link layer address associated with a given Internet layer address.
This data model intends to describe the processing that a protocol finds the hardware address, also known as Media Access Control (MAC) address, of a host from its known IP address. These tasks include, but are not limited to, adding a static entry in the ARP cache, configuring dynamic ARP learning, proxy ARP, gratuitous ARP. There are two kind of ARP configurations: global ARP configuration, which is across all interfaces on the device, and per interface ARP configuration.
ARP caching is the method of storing network addresses and the associated data-link addresses in memory for a period of time as the addresses are learned. This minimizes the use of valuable network resources to broadcast for the same address each time a datagram is sent.
There are static ARP cache entries and dynamic ARP cache entries. Static entries are manually configured and kept in the cache table on a permanent basis. Dynamic entries are added by vendor software, kept for a period of time, and then removed. We can specify how long an entry remains in the ARP cache. If we specify a timeout of 0 seconds, entries are never cleared from the ARP cache.
Proxy ARP [RFC1027] can be configured to enable the switch to respond to ARP queries for network addresses by offering its own Ethernet media access control (MAC) address. With proxy ARP enabled, the switch captures and routes traffic to the intended destination.
Gratuitous ARP requests help detect duplicate IP addresses. A gratuitous ARP is a broadcast request for a router's own IP address. If a router or switch sends an ARP request for its own IP address and no ARP replies are received, the router- or switch-assigned IP address is not being used by other nodes. However, if a router or switch sends an ARP request for its own IP address and an ARP reply is received, the router- or switch-assigned IP address is already being used by another node.
This module has one top level container, ARP, which consists of two second level containers, which are used for static entries configuration and global parameters control.
module: ietf-arp
+--rw arp
+--rw dynamic-learning? boolean
+--rw proxy-arp? boolean
+--rw global-static-entries {global-static-entries}?
+--rw static-entry* [ip-address]
+--rw ip-address inet:ipv4-address-no-zone
+--rw mac-address yang:mac-address
augment /if:interfaces/if:interface:
+--rw arp
+--rw expiry-time? uint32
+--rw learn-disable? boolean
+--rw proxy
| +--rw mode? enumeration
+--rw probe
| +--rw interval? uint8
| +--rw times? uint8
| +--rw unicast? boolean
+--rw gratuitous
| +--rw enable? boolean
| +--rw interval? uint32
| +--rw drop? boolean
+--ro statistics
+--ro in-requests-pkts? yang:counter32
+--ro in-replies-pkts? yang:counter32
+--ro in-gratuitous-pkts? yang:counter32
+--ro out-requests-pkts? yang:counter32
+--ro out-replies-pkts? yang:counter32
+--ro out-gratuitous-pkts? yang:counter32
augment /if:interfaces/if:interface/ip:ipv4/ip:neighbor:
+--ro remaining-expiry-time? uint32
This section presents the ARP YANG module defined in this document.
This module imports definitions from Common YANG Data Types, A YANG Data Model for Interface Management, and A YANG Data Model for IP Management.
<CODE BEGINS>file "ietf-arp@2018-08-01.yang"
module ietf-arp {
yang-version 1.1;
namespace "urn:ietf:params:xml:ns:yang:ietf-arp";
prefix arp;
import ietf-inet-types {
prefix inet;
reference "RFC 6991: Common YANG Data Types";
}
import ietf-yang-types {
prefix yang;
reference "RFC 6991: Common YANG Data Types";
}
import ietf-interfaces {
prefix if;
reference "RFC 8343: A Yang Data Model for Interface Management";
}
import ietf-ip {
prefix ip;
reference "RFC 8344: A Yang Data Model for IP Management";
}
organization
"IETF Routing Area Working Group (rtgwg)";
contact
"WG Web: <http://tools.ietf.org/wg/rtgwg/>
WG List: <mailto: rtgwg@ietf.org>
Editor: Xiaojian Ding
wjswsl@163.com
Editor: Feng Zheng
habby.zheng@huawei.com
Editor: Robert Wilton
rwilton@cisco.com";
description
"Address Resolution Protocol (ARP) management, which includes
static ARP configuration, dynamic ARP learning, ARP entry query,
and packet statistics collection.
Copyright (c) 2016 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
(http://trustee.ietf.org/license-info).
This version of this YANG module is part of RFC XXXX; see the RFC
itself for full legal notices.";
revision 2018-08-01 {
description
"Init revision";
reference "RFC XXXX: A Yang Data Model for ARP";
}
feature global-static-entries {
description
"This feature indicates that the device allows static entries
to be configured globally.";
}
container arp {
description
"Address Resolution Protocol (ARP) management, which includes
static ARP configuration, dynamic ARP learning, ARP entry
query, and packet statistics collection.";
leaf dynamic-learning {
type boolean;
default "true";
description
"Controls the default dynamic ARP learning behavior on all
interfaces on the device:
true - dynamic learning is enabled on all interfaces by
default,
false - dynamic learning is disabled on all interfaces by
default";
}
leaf proxy-arp {
type boolean;
default "true";
description
"Controls the default proxy ARP behavior on all interfaces
on the device:
true - proxy ARP is enabled on interfaces by default,
false - proxy APR is disabled on interfaces by default";
}
container global-static-entries {
if-feature "global-static-entries";
description
"Set a global static ARP entry, which is independent of the
interface.";
list static-entry {
key "ip-address";
description
"List of ARP static entries that can be configured
globally.";
leaf ip-address {
type inet:ipv4-address-no-zone;
description
"IP address, in dotted decimal notation.";
}
leaf mac-address {
type yang:mac-address;
mandatory true;
description
"MAC address in the format of H-H-H, in which H is a
hexadecimal number of 1 to 4 bits.";
}
}
}
}
augment "/if:interfaces/if:interface" {
description
"Augment interfaces with ARP configuration and state.";
container arp {
description
"Dynamic ARP related configuration and state";
leaf expiry-time {
type uint32 {
range "60..86400";
}
units "seconds";
description
"Aging time of a dynamic ARP entry.";
}
leaf learn-disable {
type boolean;
default "false";
description
"Whether dynamic ARP learning is disabled on an interface:
If the value is True, dynamic ARP learning is disabled.
If the value is False, dynamic ARP learning is enabled.";
}
container proxy {
description
"Configuration parameters for proxy ARP";
leaf mode {
type enumeration {
enum DISABLE {
description
"The system should not respond to ARP requests that
do not specify an IP address configured on the local
subinterface as the target address.";
}
enum REMOTE_ONLY {
description
"The system responds to ARP requests only when the
sender and target IP addresses are in different
subnets.";
}
enum ALL {
description
"The system responds to ARP requests where the sender
and target IP addresses are in different subnets, as
well as those where they are in the same subnet.";
}
}
default "DISABLE";
description
"When set to a value other than DISABLE, the local system
should respond to ARP requests that are for target
addresses other than those that are configured on the
local subinterface using its own MAC address as the
target hardware address. If the REMOTE_ONLY value is
specified, replies are only sent when the target address
falls outside the locally configured subnets on the
interface, whereas with the ALL value, all requests,
regardless of their target address are replied to.";
reference
"RFC1027: Using ARP to Implement Transparent Subnet
Gateways";
}
}
container probe {
description
"Common configuration parameters for all ARP probe.";
leaf interval {
type uint8 {
range "1..5";
}
units "second";
description
"Interval for detecting dynamic ARP entries.";
}
leaf times {
type uint8 {
range "0..10";
}
description
"Number of aging probe attempts for a dynamic ARP entry.
If a device does not receive an ARP reply message after
the number of aging probe attempts reaches a specified
number,thedynamic ARP entry is deleted.";
}
leaf unicast {
type boolean;
default "false";
description
"Send unicast ARP aging probe messages for a dynamic ARP
entry.";
}
}
container gratuitous-arp {
description
"Configure gratuitous ARP.";
leaf enable {
type boolean;
default "false";
description
"Enable or disable sending gratuitous ARP packet on
interface.";
}
leaf interval {
type uint32 {
range "1..86400";
}
units "second";
description
"The interval of sending gratuitous ARP packet on the
interface.";
}
leaf drop {
type boolean;
default "false";
description
"Drop the receipt of gratuitous ARP packets on the
interface.";
}
}
container statistics {
config false;
description
"IP ARP Statistics information on interfaces";
leaf in-requests-pkts {
type yang:counter32;
description
"Total ARP requests received";
}
leaf in-replies-pkts {
type yang:counter32;
description
"Total ARP replies received";
}
leaf in-gratuitous-pkts {
type yang:counter32;
description
"Total gratuitous ARP received";
}
leaf out-requests-pkts {
type yang:counter32;
description
"Total ARP requests sent";
}
leaf out-replies-pkts {
type yang:counter32;
description
"Total ARP replies sent";
}
leaf out-gratuitous-pkts {
type yang:counter32;
description
"Total gratuitous ARP sent";
}
}
}
}
augment "/if:interfaces/if:interface/ip:ipv4/ip:neighbor" {
description
"Augment neighbor list with parameters of ARP, eg., support for
remaining expiry time query on interfaces.";
leaf remaining-expiry-time {
type uint32;
config false;
description
"Remaining expiry time of a dynamic ARP entry. ";
}
}
}
This section presents a simple but complete example of configuring static ARP entries and dynamic learning, based on the YANG modules specified in Section 4.
Requirement:
Enable static ARP entry global configuration (not rely on interface).
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<arp xmlns="urn:ietf:params:xml:ns:yang:ietf-arp">
<static-tables>
<ip-address> 10.2.2.3 </ip-address>
<mac-address> 00e0-fc01-0000 </mac-address>
</static-tables>
</arp>
Requirement:
Enable static ARP entry configuration on interface (defined in
draft [I-D.ietf-netmod-rfc7277bis]).
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<ipv4 xmlns="urn:ietf:params:xml:ns:yang:ietf-ip">
<neighbor>
<ip-address> 10.2.2.3 </ip-address>
<mac-address> 00e0-fc01-0000 </mac-address>
<if-name> GE1/0/1 </if-name>
</neighbor>
</ipv4>
Requirement:
Enable ARP dynamic learning configuration.
<config xmlns:xc="urn:ietf:params:xml:ns:netconf:base:1.0">
<arp xmlns="urn:ietf:params:xml:ns:yang:ietf-arp">
<if-name> GE1/0/1 </if-name>
<expire-time>1200</expire-time>
<learn-disable>false</learn-disable>
<proxy-enable>false</proxy-enable>
<probe>
<interval>5</interval>
<times>3</times>
<unicast>false</unicast>
</probe>
<gratuitous>
<gratuitous-enable>false<gratuitous-enable>
<interval>60</interval>
<drop>false</drop>
<gratuitous>
</arp>
This document registers a URI in theIETF XML registry. Following the format in [RFC3688], the following registration is requested to be made:
URI: urn:ietf:params:xml:ns:yang:ietf-arp Registrant Contact: The IESG. XML: N/A, the requested URI is an XML namespace.
This document registers a YANG module in the YANG Module Names registry [RFC7950].
Name: ietf-arp Namespace: urn:ietf:params:xml:ns:yang: ietf-arp Prefix: arp Reference: RFC XXXX
The YANG module defined in this document is designed to be accessed via YANG based management protocols, such as NETCONF [RFC6241] and RESTCONF [RFC8040]. Both of these protocols have mandatory-to- implement secure transport layers (e.g., SSH, TLS) with mutual authentication.
The NETCONF access control model (NACM) [RFC8341] provides the means to restrict access for particular users to a pre-configured subset of all available protocol operations and content.
There are a number of data nodes defined in this YANG module that are writable/creatable/deletable (i.e., config true, which is the default). These data nodes may be considered sensitive or vulnerable in some network environments. Write operations (e.g., edit-config) to these data nodes without proper protection can have a negative effect on network operations.
These are the subtrees and data nodes and their sensitivity/vulnerability:
The authors wish to thank Alex Campbell and Reshad Rahman, Qin Wu, Tom Petch, many others for their helpful comments.
| [RFC6241] | Enns, R., Bjorklund, M., Schoenwaelder, J. and A. Bierman, "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, June 2011. |
| [RFC8040] | Bierman, A., Bjorklund, M. and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, January 2017. |
| [RFC8340] | Bjorklund, M. and L. Berger, "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. |