HSRP Issues on VLAN interfaces

Question

We are experiencing an issue with HSRP and VLANS. We have the VLANS tracked to physical interfaces, with the default decrement value of 10.
When we physically fail the fiber circuit (pull fiber transmit) the physical port reports down condition. The VLAN reports that it is still up. BOTH routers report that they are the active router and connectivity is lost.
When the physical port is shut down, the failover takes place and the routers report their state as predicted.
Any help would be greatly appreciated.
These routers are 4506's running 12.1(19)EW code
on WS-X4515 module.

Answer 1

If there are still active ports, then I would expect the VLAN interface to stay UP on both routers. However, I would not normally expect both routers to be ACTIVE. Could it be that when you take down these physical links, that the routers lose sight of each other as far as the Hellos are concerned?
About the "If there are still active ports" bit ... don't gorget that a trunk can also constitute an active port in this sense. So if you have go any access switches uplinked to these 4506s, the trunks will be enough to keep the VLAN interface alive.
Remember also that HSRP has a hold time of only 9 seconds by default, whereas 802.1d Spanning Tree has a convergence time up to 50 seconds by default. So it is possible that if the link you are disconnecting is the active root port of a switch, that the two HSRP routers will lose sight of each other. In that case,they can both become active for a few seconds. Effectively, during the STP convergence the VLAN can be partitioned. It all depends on your topology.
You are pulling only the transmit fiber. I wonder if enabling UDLD would help here.
As Georg says, it would be useful to know a bit more about the topology and the configuration.
Kevin Dorrell
Luxembourg