OSPF on LAN with HSRP

[gbraver]

Rather than opening a case would like to understand how OSPF works on a lan when we have HSRP active.

To describe the issue I have three l3 switches tied A - B - C all running ospf and on the same vlan.  HSRP runs between B and C with C being both the HSRP primary and the DR for the LAN.

On A I show two routes shared networks on B and C but the preferred path is through B.  Should this be the case?  Any easy way to have the preferred path be A - C?

Thanks

[kevin.szatkowski]

HSRP and OSPF are on two different layers, so OSPF is advertising out the physical interface vs the HSRP interface.  To change the preferred path just lower the cost on the interface router c to a.  I'm not sure what your trying to accomplish running HSRP and OSPF since OSPF will change the path if b or c go down.

[Joseph W. Doherty]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

As Kevin has already noted, HSRP and OSPF aren't really related.

I've seen those new to the combination, try to use HSRP IPs with OSPF, but that's an incorrect approach.

Traffic path preference, when both HSRP and OSPF are in use depends on their configurations and the network topology.  You've provided insufficient information to say whether the current preferred  path should be the case.

As to an easy way to change paths, with HSRP, you determine which physical gateway is the active gateway.  With OSPF, you adjust interface costs to change path preferences.