Figure 8: Basic Vrrp - Juniper EX9200 Features Manual

High Availability Feature Guide for EX9200 Switches
120
VRRP for IPv6 provides a much faster switchover to an alternate default router than IPv6
neighbor discovery procedures. Typical deployments use only one backup router.
Figure 8 on page 120 illustrates a basic VRRP topology. In this example, Routers A, B, and
C are running VRRP and together make up a virtual router. The IP address of this virtual
router is 10.10.0.1 (the same address as the physical interface of Router A).

Figure 8: Basic VRRP

Because the virtual router uses the IP address of the physical interface of Router A, Router
A is the master VRRP router, while routers B and C function as backup VRRP routers.
Clients 1 through 3 are configured with the default gateway IP address of 10.10.0.1. As the
master router, Router A forwards packets sent to its IP address. If the master virtual router
fails, the router configured with the higher priority becomes the master virtual router and
provides uninterrupted service for the LAN hosts. When Router A recovers, it becomes
the master virtual router again.
NOTE: In Junos OS Release 14.2R1, in some cases, during an inherit session,
there is a small time frame during which two routers are in Master-Master
state. In such cases, the VRRP groups that inherit the state do send out VRRP
advertisements every 120 seconds. So, it takes the routers up to 120 seconds
to recover after moving to Master-Backup state from Master-Master state.
VRRP is defined in RFC 3768, Virtual Router Redundancy Protocol. VRRP for IPv6 is defined
in draft-ietf-vrrp-ipv6-spec-08.txt, Virtual Router Redundancy Protocol for IPv6. See also
draft-ietf-vrrp-unified-mib-06.txt, Definitions of Managed Objects for the VRRP over IPv4
and IPv6.
NOTE: Even though VRRP, as defined in RFC 3768, does not support
authentication, the Junos OS implementation of VRRP supports
authentication as defined in RFC 2338. This support is achieved through the
backward compatibility options in RFC 3768.
Copyright © 2017, Juniper Networks, Inc.