Ip-Redundancy Show; Vrrp Configuration Notes - Cabletron Systems SmartSwitch Router User's Reference Manual

Chapter 14: VRRP Configuration Guide

ip-redundancy show

The ip-redundancy show command reports information about a VRRP configuration. To
display VRRP information, enter the following commands in Enable mode.
Display information about all
virtual routers.
Display information about all
virtual routers on a specified
interface.
Display detailed statistics about
a specific virtual router

VRRP Configuration Notes

• The Master router sends keep-alive advertisements. The frequency of these keep-alive
advertisements is determined by setting the Advertisement interval parameter. The
default value is 1 second.
• If a Backup router doesn't receive a keep-alive advertisement from the current Master
within a certain period of time, it will transition to the Master state and start sending
advertisements itself. The amount of time that a Backup router will wait before it
becomes the new Master is based on the following equation:
Master-down-interval = (3 * advertisement-interval) + skew-time
The skew-time depends on the Backup router's configured priority:
Skew-time = ( (256 - Priority) / 256 )
Therefore, the higher the priority, the faster a Backup router will detect that the Master
is down. For example:
– Default advertisement-interval = 1 second
– Default Backup router priority = 100
– Master-down-interval = time it takes a Backup to detect the Master is down
= (3 * adv-interval) + skew-time
= (3 * 1 second) + ((256 - 100) / 256)
= 3.6 seconds
• If a Master router is manually rebooted, or if its interface is manually brought down, it
will send a special keep-alive advertisement that lets the Backup routers that a new
Master is needed immediately.
206
ip-redundancy show vrrp
ip-redundancy show vrrp interface
ip-redundancy show vrrp
<interface>
verbose
SmartSwitch Router User Reference Manual
<interface>
<vrid>
interface