Cabletron Systems SmartSwitch Setting the Backup Priority, Setting the Advertisement Interval

Chapter 7: VRRP Configuration Guide

Setting the Backup Priority

As described in “Multi-Backup Configuration” on page 99, you can specify which Backup router takes over when the Master router goes down by setting the priority for the Backup routers. To set the priority for a Backup router, enter the following command in Configure mode:

Set the Backup priority for a virtual router.

ip-redundancy set vrrp <vrid> interface <interface> priority <number>

The priority can be between 1 (lowest) and 254. The default is 100. The priority for the IP address owner is 255 and cannot be changed.

Setting the Advertisement Interval

The VRRP Master router sends periodic advertisement messages to let the other routers know that the Master is up and running. By default, advertisement messages are sent once each second. To change the VRRP advertisement interval, enter the following command in Configure mode:

Set the Advertisement interval for a virtual router.

ip-redundancy set vrrp <vrid> interface <interface> adv-interval <seconds>

Setting Pre-empt Mode

When a Master router goes down, the Backup with the highest priority takes over the IP addresses associated with the Master. By default, when the original Master comes back up again, it takes over from the Backup router that assumed its role as Master. When a VRRP router does this, it is said to be in pre-empt mode. Pre-empt mode is enabled by default on the SSR. You can prevent a VRRP router from taking over from a lower-priority Master by disabling pre-empt mode. To do this, enter the following command in Configure mode:

Disable pre-empt mode for a virtual router.

ip-redundancy set vrrp <vrid> interface

<interface> preempt-mode disabled

Note: If the IP address owner is available, then it will always take over as the Master, regardless of whether pre-empt mode is on or off.

104 SmartSwitch Router User Reference Manual