Cannot ping SVI from fiber downlink switch

[jeansfeng]

I have three Cisco 3750G (#1, #2 and #3) stacked as core switch. Each switch has fiber ports downlink with Cisco 2960.

The problem is I cannot ping the SVI interface from 2960  if it's connected to the #2 switch with fiber cable. it works properly in last week before this problem happen.

It works if I uplink the 2960 with copper cable to any core switch, it also works if I connect 2960 to the fiber port of #1 or #3.  It looks all fiber ports on the #2 switch cannot route data .

I tried to reload the #2 switch individually. 2960 can ping SVI for few minutes after reboot, then the problem comes again.

Is it a hardware problem or configuration issues?

[jeansfeng]

is there anyone can help on it?

[Jean-Luc OURMET]

Hello

HAve you looked at spanning tree :

show spanning-tree blockedports

Regards

Jean-Luc

[jeansfeng]

Hello ,

I'm appreciated for you replay. This problem was by replacing #2 swtich with a spare one, without changing the stack.

I think It should be hareware problem on Fiber data process module.

[Deben Bhattarai]

HI , Have you check properly that replaced switch is a part of switch stack.