HSRP and traceroute

[minoc]

Hello all,

I have a configuration of HSRP with two 7200 routers over ATM LANE and GE subinterfaces.

Everything is working fine, when the primary router goes down the secundary takes over as expected. My question is with traceroutes. From a host connected to the same segment as the GE interface doing traceroute, the first hop shown is the physical interface IP address of the primary router and not the virtual one. Is this the correct behavior?, the host can ping both pysical and virtual Ip address of the routers.

Another question I have is, when both routers are using OSPF, do packets can travel in a asymetric manner?, I mean traffic could go trough the primary router and come back using the secondary router?.

Regards,

Carlos Roque

[Craig Norborg]

If I'm not wrong, traceroute will always return the physical interfaces IP address, not the virtual one.

Is the second hop the IP address of the secondary router? If so, that means that your traffic is still going through the first router and then being rerouted through the second router. Possibly the route is still hanging on across the first link either by OSPF not dropping it or maybe its configured as a static route? You might also try using the "standby track" parameter to lower the priority of that router when the interface goes down so the second router can become the primary.

[ruwhite]

This is correct--the router will never source traffic from the virtual hsrp address.

:-)

Russ

[minoc]

Where can I find more information on HSRP, specifically with icmp's. traceroutes and applications behavior.

Regards,

Carlos Roque

[ruwhite]

http://www.cisco.com/en/US/tech/tk648/tk362/tk321/tech_protocol_home.html

Is the best place for information on HSRP in general. I don't think they mention anything about traceroutes, pings, and other such things there, though.

:-)

Russ.W

[minoc]

Thanks for your replay.

Both routers are connected to the ATM cloud using ELANS. Each subinterface is configured with HSRP the 7206 been as the primary for HSRP. Under OSPF each link in both routers will have the same cost. OSPF I think will load balance, right?.

On the ATM side the HSRP configuration is tracking interface ge0/0. On the GE side the tracking was setup to monitor the physical TM interface.

Regards,

Carlos Roque

[ruwhite]

As long as there are two equal cost routes, then OSPF will install both of them in the routing table, and routing/cef will load share between them.

:-)

Russ.W