HSRP Interface Tracking Question

[rkallas]

I have a pair of 7206 routers for Internet access.  The Internet was provided over OC3, and used interface POS1/0.  I just upgraded the Internet to Ethernet so now the interface is GigabitEthernet 0/3.

I just discovered that there there is another interface that uses POS1/0 as an HSRP tracking interface.  So my question is:   Can I just remove the old tracking interface and add the new one? Or is there another prefered method to do this?

My current HSRP interface:

interface GigabitEthernet0/1.21
 description INET
 encapsulation dot1Q 21
 ip address x.x.x.x 255.255.255.240
 ip broadcast-address x.x.x.x
 no ip redirects
 ip accounting output-packets
 ip flow ingress
 ip nbar protocol-discovery
 no snmp trap link-status
 standby 1 ip x.x.x.x
 standby 1 priority 105
 standby 1 preempt
 standby 1 track POS1/0
 

Thanks!

Ray

[Jon Marshall]

Ray

You mean the LAN interface was tracking the WAN interface and now that interface has changed ?

If so then yes just update your HSRP configuration to reflect the new interface assuming you are not using the previous interface for anything any more.

Edit - if you aren't using the previous interface any more I would have thought your HSRP would have failed over ?

Jon

[rkallas]

Thanks John,

Yes that's correct.  The LAN interfaces were tracking the WAN interface.  And POS1/0 is now shutdown. 

I appreciate the quick reply.

Ray

[Richard Burts]

Ray

While it is correct that you can just change the HRP interface to track the Ethernet interface be aware that it may not work quite the same way. With POS and most serial interface implementations if communications with the peer is lost then the loss of keepalives will change the interface state to line protocol down and that is what the interface tracking is looking for. However with an Ethernet interface if you lose communication with the peer the interface may still be in a line protocol up state. In that circumstance interface tracking will not detect the problem.

HTH

Rick