HSRP Flap after inserting an RJ45 card

[sassi-zied]

Hi All,

We have 2 Cisco 7609-S router with SRD3 version . We have detected a very strange behavior when we insert a new RJ45 into one of them  HSRP start to flap (vlan pass from inti , active ; standby etc ) and we have a total loss of service. The problem is when we removed the card HSRP is still flapping. notice that with SRE3 version we got instant HSRP flap but the situation is stable after a while. But on SRD3 it's not the case.

Have you seen similar problem before ? What are the cause of these flap ? Is this a bug ? What are the recommendation by Cisco when inserting a new module (optical or electrical card) ?

Thank you

Regards,

Zied

[Amit Aneja]

Some possibilities:

1) The cpu was momentarily too busy after the OIR.

2) Bus stall: The bus stall happens as a linecard is inserted into chassis. The

duration of 'stall' depends on how long it takes to insert the card

(user dependent). When the long pin of a linecard connects to backplane,

it stalls the bus, till the short pins are connected properly to the

backplane.

3) Unstable STP, I would look at "show spanning-tree vlan x" for the vlan which was showing the HSRP flaps.

I wuld look for the no. of Topology change notifications.

4) Aggresive HSRP timers, this could be the most common reason.

I remember seeing a bug as well on 6500, CSCsl22845

[sassi-zied]

Hi Amaneja,

Thank you for your feedback

Zied