|Internet-Draft||YANG VRRP||September 2023|
|Lindem, et al.||Expires 8 March 2024||[Page]|
- Network Working Group
- 8347 (if approved)
- Intended Status:
- Standards Track
A YANG Data Model for the Virtual Router Redundancy Protocol (VRRP)
This document describes a data model for the Virtual Router Redundancy Protocol (VRRP). Both versions 2 and 3 of VRRP are covered.¶
The VRRP terminology has been updated conform to inclusive language guidelines for IETF technologies. The IETF has designated National Institute of Standards and Technology (NIST) "Guidance for NIST Staff on Using Inclusive Language in Documentary Standards" for its inclusive language guidelines.¶
This document obsoletes RFC 8347.¶
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 8 March 2024.¶
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.¶
This document introduces a YANG data model [RFC6020] [RFC7950] for the Virtual Router Redundancy Protocol (VRRP) [RFC3768] [RFC5798]. VRRP provides higher resiliency by specifying an election protocol that dynamically assigns responsibility for a virtual router to one of the VRRP routers on a LAN.¶
The YANG module specified in this document supports both versions 2 and 3 of VRRP. VRRP version 2 (defined in [RFC3768]) supports IPv4. VRRP version 3 (defined in [RFC5798]) supports both IPv4 and IPv6.¶
The VRRP terminology has been updated conform to inclusive language guidelines for IETF technologies. The IETF has designated National Institute of Standards and Technology (NIST) "Guidance for NIST Staff on Using Inclusive Language in Documentary Standards" [NISTIR8366] for its inclusive language guidelines. This document obsoletes VRRP Version 3 [RFC8347].¶
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.¶
In this document, names of data nodes, actions, and other data model objects are often used without a prefix, as long as it is clear from the context in which YANG module each name is defined. Otherwise, names are prefixed using the standard prefix associated with the corresponding YANG module, as shown in Table 1.¶
The model covers VRRP version 2 [RFC3768] and VRRP version 3 [RFC5798]. The model is designed to be implemented on a device where VRRP version 2 or 3 is implemented. With the help of a proper management protocol, the defined model can be used to:¶
In the above figure, a tree node without a prefix is from the model "ietf-interfaces". A tree node with prefix "ip:" is from the model "ietf-ip". A tree node with prefix "vrrp:" is from the VRRP model specified in this document.¶
The "vrrp" container contains a list of vrrp-instance nodes, which are instantiated under an interface for a specified address family (IPv4 or IPv6).¶
Each vrrp-instance node represents a VRRP router state machine, as described in Section 6.4 of [RFC5798], providing the configuration and state information for the election process of a virtual router. The IP addresses on the augmented interface are the real addresses through which the VRRP router operates. The IPv4 or IPv6 address or addresses associated with a virtual router (described in Section 1 of [RFC5798]) are modeled as a list of IPv4 or IPv6 addresses under the vrrp-instance.¶
The model structure for the protocol configuration is as shown below:¶
The model allows the following protocol entities to be configured:¶
The model structure for the protocol states is as shown below:¶
This model conforms to the Network Management Datastore Architecture (NMDA) [RFC8342]. The operational state data is combined with the associated configuration data in the same hierarchy [RFC8407]. When protocol states are retrieved from the NMDA operational state datastore, the returned states cover all "config true" (rw) and "config false" (ro) nodes defined in the schema.¶
The model allows the retrieval of protocol states at the following levels:¶
- VRRP instance (version 2 or 3), representing a VRRP router.¶
- Virtual IPv4 or IPv6 address associated with a virtual router.¶
- Tracking interface, to detect interface connectivity failures.¶
- Tracking network, to detect network connectivity failures.¶
- Global states and statistics summarizing all instances.¶
This model defines the following VRRP-specific notifications:¶
Each notification type is used to indicate a type of VRRP state change or error occurrence:¶
VRRP new active event, indicating that a new active virtual router has been elected.¶
VRRP protocol error event for a message that fails to reach a VRRP instance to be processed.¶
VRRP virtual router error event for a message processed on a VRRP instance.¶
The VRRP YANG data model defined in this document has the following tree structure:¶
The YANG module specified 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 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 [RFC5246].¶
The NETCONF access control model [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.¶
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:¶
Unauthorized access to any data node of these subtrees can adversely affect the routing subsystem of both the local device and the network. This may lead to network malfunctions, delivery of packets to inappropriate destinations, and other problems.¶
Some of the readable data nodes in this 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:¶
Unauthorized access to any data node of these subtrees can disclose the operational state information of VRRP on this device.¶
- "Guidance for NIST Staff on Using Inclusive Language in Documentary Standards, National Institute of Standards and Technology (NIST) Interagency or Internal Report 8366", NISTIR 8366, , <https://doi.org/10.6028/NIST.IR.8366>.
- Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, , <https://www.rfc-editor.org/info/rfc2119>.
- Jewell, B. and D. Chuang, "Definitions of Managed Objects for the Virtual Router Redundancy Protocol", RFC 2787, DOI 10.17487/RFC2787, , <https://www.rfc-editor.org/info/rfc2787>.
- Mealling, M., "The IETF XML Registry", BCP 81, RFC 3688, DOI 10.17487/RFC3688, , <https://www.rfc-editor.org/info/rfc3688>.
- Dierks, T. and E. Rescorla, "The Transport Layer Security (TLS) Protocol Version 1.2", RFC 5246, DOI 10.17487/RFC5246, , <https://www.rfc-editor.org/info/rfc5246>.
- Nadas, S., Ed., "Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6", RFC 5798, DOI 10.17487/RFC5798, , <https://www.rfc-editor.org/info/rfc5798>.
- Bjorklund, M., Ed., "YANG - A Data Modeling Language for the Network Configuration Protocol (NETCONF)", RFC 6020, DOI 10.17487/RFC6020, , <https://www.rfc-editor.org/info/rfc6020>.
- Enns, R., Ed., Bjorklund, M., Ed., Schoenwaelder, J., Ed., and A. Bierman, Ed., "Network Configuration Protocol (NETCONF)", RFC 6241, DOI 10.17487/RFC6241, , <https://www.rfc-editor.org/info/rfc6241>.
- Wasserman, M., "Using the NETCONF Protocol over Secure Shell (SSH)", RFC 6242, DOI 10.17487/RFC6242, , <https://www.rfc-editor.org/info/rfc6242>.
- Tata, K., "Definitions of Managed Objects for Virtual Router Redundancy Protocol Version 3 (VRRPv3)", RFC 6527, DOI 10.17487/RFC6527, , <https://www.rfc-editor.org/info/rfc6527>.
- Schoenwaelder, J., Ed., "Common YANG Data Types", RFC 6991, DOI 10.17487/RFC6991, , <https://www.rfc-editor.org/info/rfc6991>.
- Bjorklund, M., Ed., "The YANG 1.1 Data Modeling Language", RFC 7950, DOI 10.17487/RFC7950, , <https://www.rfc-editor.org/info/rfc7950>.
- Bierman, A., Bjorklund, M., and K. Watsen, "RESTCONF Protocol", RFC 8040, DOI 10.17487/RFC8040, , <https://www.rfc-editor.org/info/rfc8040>.
- Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, , <https://www.rfc-editor.org/info/rfc8174>.
- Bierman, A. and M. Bjorklund, "Network Configuration Access Control Model", STD 91, RFC 8341, DOI 10.17487/RFC8341, , <https://www.rfc-editor.org/info/rfc8341>.
- Bjorklund, M., Schoenwaelder, J., Shafer, P., Watsen, K., and R. Wilton, "Network Management Datastore Architecture (NMDA)", RFC 8342, DOI 10.17487/RFC8342, , <https://www.rfc-editor.org/info/rfc8342>.
- Bjorklund, M., "A YANG Data Model for Interface Management", RFC 8343, DOI 10.17487/RFC8343, , <https://www.rfc-editor.org/info/rfc8343>.
- Bjorklund, M., "A YANG Data Model for IP Management", RFC 8344, DOI 10.17487/RFC8344, , <https://www.rfc-editor.org/info/rfc8344>.
- Liu, X., Ed., Kyparlis, A., Parikh, R., Lindem, A., and M. Zhang, "A YANG Data Model for the Virtual Router Redundancy Protocol (VRRP)", RFC 8347, DOI 10.17487/RFC8347, , <https://www.rfc-editor.org/info/rfc8347>.
- Hinden, R., Ed., "Virtual Router Redundancy Protocol (VRRP)", RFC 3768, DOI 10.17487/RFC3768, , <https://www.rfc-editor.org/info/rfc3768>.
- Bjorklund, M., "IANA Interface Type YANG Module", RFC 7224, DOI 10.17487/RFC7224, , <https://www.rfc-editor.org/info/rfc7224>.
- Lhotka, L., "JSON Encoding of Data Modeled with YANG", RFC 7951, DOI 10.17487/RFC7951, , <https://www.rfc-editor.org/info/rfc7951>.
- Bjorklund, M. and L. Berger, Ed., "YANG Tree Diagrams", BCP 215, RFC 8340, DOI 10.17487/RFC8340, , <https://www.rfc-editor.org/info/rfc8340>.
- Bierman, A., "Guidelines for Authors and Reviewers of Documents Containing YANG Data Models", BCP 216, RFC 8407, DOI 10.17487/RFC8407, , <https://www.rfc-editor.org/info/rfc8407>.
- Voit, E., Clemm, A., Gonzalez Prieto, A., Nilsen-Nygaard, E., and A. Tripathy, "Subscription to YANG Notifications", RFC 8639, DOI 10.17487/RFC8639, , <https://www.rfc-editor.org/info/rfc8639>.
- Clemm, A. and E. Voit, "Subscription to YANG Notifications for Datastore Updates", RFC 8641, DOI 10.17487/RFC8641, , <https://www.rfc-editor.org/info/rfc8641>.
This section contains an example of an instance data tree in JSON encoding [RFC7951], containing both configuration and state data. (This example includes "iana-if-type", which is defined in [RFC7224].)¶
The configuration instance data for Router 1 in the above figure could be as follows:¶
The corresponding operational state data for Router 1 could be as follows:¶