[c-nsp] 6500 MAC learning issue.

Alex Cruz Farmer alex.cf+c-nsp at netsumo.com
Sun Jun 10 07:44:33 EDT 2007


Hi,

On Saturday morning I deployed a 6500/SUP2 chassis running, s222-advipservicesk9_wan-mz.122-18.SXF5.bin. Since the deployment, there
have been complaints of what looks like mac-learning issues. I've managed to come to this conclusion because, if you, for example, ping
a box in one direction (say West to East) within the first, what seems to be, 5-10 minutes it dies.

I've not yet tried reloading the box to see if this makes a difference, as it's considered "live". The irritating problem is, the issue
does not affect *every* Vlan, only a few.

If for example, I create a layer3 interface on the suspected 6500 with an IP, ping the box which is having issues, the box will then
return. So the problem seems that mac-learning East to West is having problems, but when a layer2 packet from West to East is sent, it
will go down after 10 minutes.

(6500-B is the problematic one, it's using the 2 Gbic slots on the supervisor, so Gi1/1 goes to 3550-B, and Gi1/2 goes to 3550-A)

Topology:

6500-A - 3550-A - 6500-B - 3550-B - 6500-C

If anyone has any suggestions that would be fantastic. I may try and move the Gig port over to another module on the 6500 instead of
terminating in the supervisor to see if that makes a difference.

Thanks,



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