Tracking Interface Status

[Alain Desnoyers]

I've started researching how I would track the status of an interface that is not local to the router. For example. I have a Core Router that has connections to 2 routers (1 router connects to an MPLS cloud and the other router connects to the Internet) I want to use a route map on the Core router to set the ip next hop for specific traffic arriving at the Core Router from the LAN to use the Internet router. My problem is if the Internet connection goes down on the Internet router all traffic being sent to that next hop router will not failover and use the MPLS connection. I want to be able to track the Internet router's Internet interface from the Core Router. Is this even possible.

Thanks

[skarthic · Accepted solution]

Tracking an interface is possible using Cisco IPSla ICMP Echo feature. Read the below link

http://www.cisco.com/en/US/docs/ios/12_4/ip_sla/configuration/guide/hsicmp.html

You can then use the output from tracking to be used as a part of a route map that is used in Policy based routing.

Regards,

Subramaniya Karthic

[Alain Desnoyers]

Thanks for the info, that sounded really good until I realized my device does not support the ip sla command. It

's a layer 3 switch (3750). The Core router I referred to was in fact my layer 3 switch. I guess I'll have to continue my research.

Thanks

[skarthic · Accepted solution]

Are u sure abt that.. I checked for the feature in CFN and found that IPSLA ICMP echo feature is supported in 3750E and X

What is the IOS version in the 3750. Did you try any of the commands in the device..That should be of some help.

[Alain Desnoyers]

(C3750-IPSERVICES-M), Version 12.2(25)SEE2

[Alain Desnoyers]

It's a 3750G-48P, the other 3750s we have are 3750X running (C3750E-UNIVERSALK9-M), Version 12.2(53)SE2 and I confirmed on the 3750X that IP SLA is available, just not on the 3750G.

[Alain Desnoyers]

the precursor to ip sla is trk.

Thanks