Avaya P333R-LB, Installation And Configuration Manual

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Chapter 13 Layer 3 Redundancy
Avaya P333R-LB User’s Guide 121
SRRP
P333R-LB SRRP redundancy capabilities provide automatic backup Layer 3
switching for IP stations. P333R-LB units can be configured to back each other up so
that if one fails the other will take over its forwarding functions. The backup P333R-
LB is not idle. As long as both P333R-LB units are functional, traffic is shared
between them. The P333R-LB modules can be in the same P330 stack or in different,
connected, P330 stacks. The P333R-LB can back up another P333R-LB unit or any
other router.
A P333R-LB unit configured to back up another unit monitors the other’s status by
polling it at configured intervals, and automatically detects when the other router
fails and when it becomes functional again. When detecting a failure, the backup
P333R-LB sends a gratuitous ARP message that causes all stations to send their IP
traffic to the backup P333R-LB MAC address instead of the failed unit MAC
address. As long as it is an active backup resulting from the failure of the main unit,
the backup P333R-LB answers ARP requests for the main unit, providing its own
MAC address.
SRRP Commands
The following table displays the SRRP Commands:
Figure 13.3 SRRP Commands
In order to... Use the following command...
Display the SRRP configuration and
status show ip srrp
Configure SRRP options, activate
SRRP and enter the SRRP
configuration mode router srrp
Backup an additional interface of
the main router using the SRRP
application ip srrp backup
Configure the polling interval (in
seconds) used by SRRP poll-interval
Configure the timeout (in seconds)
after which SRRP declares the main
router dead if it does not respond to
polling timeout