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Cisco IOS Cookbook, 2nd Edition by Ian Brown, Kevin Dooley

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Making HSRP React to Problems on Other Interfaces

Problem

You want HSRP to switch to the backup router when another port on the primary router becomes unavailable.

Solution

The standby track configuration command reduces the priority of an active HSRP router into a standby mode when one of its interfaces becomes unavailable. If the priority drops far enough, another router will take over:

Router1#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router1(config)#interface FastEthernet0/1
Router1(config-if)#standby 1 ip 172.22.1.1
Router1(config-if)#standby 1 priority 120
Router1(config-if)#standby 1 preempt
Router1(config-if)#standby 1 track Serial0/0 20
Router1(config-if)#exit
Router1(config)#end
Router1#

Beginning with IOS Version 12.2(15)T, Cisco enhanced functionality by allowing you to track objects other than line-protocol state:

Router1#configure terminal 
Enter configuration commands, one per line.  End with CNTL/Z.
Router1(config)#track 11 interface Serial1/1 ip routing      
Router1(config-track)#exit                                    
Router1(config)#interface FastEthernet0/0
Router1(config-if)#standby 1 ip 172.22.1.1
Router1(config-if)#standby 1 priority 120  
Router1(config-if)#standby 1 preempt
Router1(config-if)#standby 1 track 11 decrement 50
Router1(config-if)#end
Router1#

Discussion

This configuration option is particularly useful when you have two identically configured WAN access routers using HSRP on their LAN ports. In this case, if you are using a dynamic routing protocol, then ...

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