RFC 9568: Virtual Router Redundancy Protocol (VRRP) Version 3 for IPv4 and IPv6
Recent RFCs 2024-05-01
Summary:
This document defines version 3 of the Virtual Router Redundancy
Protocol (VRRP) for IPv4 and IPv6. It obsoletes RFC 5798, which
previously specified VRRP (version 3). RFC 5798 obsoleted RFC 3768,
which specified VRRP (version 2) for IPv4. VRRP specifies an election
protocol that dynamically assigns responsibility for a Virtual Router
to one of the VRRP Routers on a LAN. The VRRP Router controlling the
IPv4 or IPv6 address(es) associated with a Virtual Router is called
the Active Router, and it forwards packets routed to these IPv4 or
IPv6 addresses. Active Routers are configured with virtual IPv4 or
IPv6 addresses, and Backup Routers infer the address family of the
virtual addresses being advertised based on the IP protocol version.
Within a VRRP Router, the Virtual Routers in each of the IPv4 and
IPv6 address families are independent of one another and always
treated as separate Virtual Router instances. The election process
provides dynamic failover in the forwarding responsibility should the
Active Router become unavailable. For IPv4, the advantage gained
from using VRRP is a higher-availability default path without
requiring configuration of dynamic routing or router discovery
protocols on every end-host. For IPv6, the advantage gained from
using VRRP for IPv6 is a quicker switchover to Backup Routers than
can be obtained with standard IPv6 Neighbor Discovery mechanisms.