User manual

23: Virtual Router Redundancy Protocol (VRRP)

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23 Virtual Router Redundancy Protocol (VRRP)

The Virtual Router Redundancy Protocol (VRRP) is a networking protocol

designed to eliminate the single point of failure inherent in the static default

routed environment.

VRRP specifies an election protocol that dynamically assigns responsibility for a

virtual router to one of the VRRP router on a LAN. The VRRP router controlling

the IP address(es) associated with a virtual router is called the Master, and

forwards packets sent to these IP addresses. The election process provides

dynamic failover in the forwarding responsibility from the Master to a Backup

router should the Master become unavailable.

This process allows the virtual router IP address(es) on the LAN to be used as

the default first hop router by end-hosts. 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.

Two or more routers forming the redundancy cluster are configures with the

same Router ID and Virtual IP address. A VRRP router group operates within the

scope of the single LAN.

Additionally, the VRRP routers are configured with its initial role (Master or

Backup) and the router priority, which is a factor in the master router election

process.

A password authentication may also be configured to protect VRRP protocol

messages against spoofing.

The VRRP protocol is implemented according to Internet standard RFC2338.

23.1 Software versions

VRRP is available on VIE, ARN, LIS and GIG software versions.

To check which software your router is running, SSH to a router and the

following information is shown.

Figure 63: Example output after accessing the router via SSH

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GW1000 Series User Manual

Issue: 2.4 Page 153 of 255