1. Introduction

Questa pagina riassume la sezione corrispondente di RFC 9983 e conserva i punti essenziali su OSPFv2, AC-Flag, IANA e YANG.

An IP prefix may be configured as anycast, and the same value can be advertised by multiple routers. Other routers benefit from knowing that an advertisement is for an anycast prefix.

[RFC7684] defines OSPFv2 Opaque Link State Advertisements (LSAs) based on Type-Length-Value (TLV) tuples. The OSPFv2 Extended Prefix TLV in the OSPFv2 Extended Prefix Opaque LSA advertises additional attributes associated with a prefix.

IS-IS [RFC9352] and OSPFv3 [RFC9513] already have extensions related to the anycast property of prefixes. This document defines a flag for OSPFv2 in the Flags field of the OSPFv2 Extended Prefix TLV Flags and specifies a companion YANG module.