Weird action of Cat.4506..

[hyukin.kwon]

Hi all,

I have two catalyst 4506s as Backbone.

There are connected with trunk(isl) each other. Of course HSRP is configured for HA between the Cat4506s. Server which has two NICs for redundancy is connected diretly to the 4506s (One is active and connected with Active 4506, the other NIC is stnadby and connected with standby 4506, they use a virtual MAC & IP address). Also the Cat.4506s have another HSRP for upper route redundancy.

The symptom is that when the upper HSRP status is changed from active to standby ( but the HSRP status for server is not changed), the Cat.4506 just transited from standby to active HSRP forwards traffics to Standby NIC of a server(there are only output traffics from 4506 to stnadby NIC of a server). this is not temporay situation . If happens, it remains the weird situation until the original active Cat.4506 recover the HSRP active status (upper HSRP).

Another symptom is when I captured the traffic to the standby NIC of a server on 4506, there is not traffic for connected server, only can see garbage traffic.

I don't know the reason

Welcome any possibilties...

TIA....

[leighharrison]

Hi there,

Is you HSRP configured into 2 different groups?

Also, what software version are you running?

Regards,

LH

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[hyukin.kwon]

Yap They are in differnet group and different vlans

The version is 12.1(19)EW1..

TIA..

[leighharrison]

Hey there,

I would raise a TAC case.

If the HSRP was on the same vlan and in the same group, then there could have been some messages picked up by mistake. As they are on different vlans and in different groups, then these messages would not be seen. But the switch must be making the decision based on something, but to me this is not normal behaviour and sounds like a bug...

Regards,

LH

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