Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

tracking a fast ethernet interface


is there a way that i can track a 100 Mbps fiber link status while running HSRP.

I'm trying to run HSRP between two routers having two links to a of them is a 100 Mbps fiberlink and the other is a T3 link.

I want the first router with 100 Mbps as my active router.but the issue is since the fastethernet interface never goes into the line protocol "down" state i'm not able to track this interface. So the second router with T3 link does not become active.

Is there a way this can be achieved..All suggestions are welcome.



New Member

Re: tracking a fast ethernet interface

Your FastE interface should go down/down during a cable/switch failure. This would allow tracking to work just fine.

What condition causes a failure of layer 1/2 connetivity, but doesn't cause a down/down?


Cisco Employee

Re: tracking a fast ethernet interface

one solution is to use a tunnel interface.

Create a loopback on each end of the 100 fiber link.

Assigned it an ip address that you will only use for the tunnel and make sure you advertise this route through a routing protocol only the the 100 fiber link.

Now, your tunnel will be up/up unless you lose the route to the destination.

Therefore, if the fiber link is still up/up but no traffic is crossing link, you won't receive the route to the loopback.

The tunnel will go into up/down state.

So, you can track the tunnel instead of fiber link.

You don't even need to use the tunnel.

I mean you can still make sure no traffic enter the tunnel. The tunnel is there just to detect that there is a problem with the fiber link.