[c-nsp] 6500 HSRP unicast flooding

Randy amps at djlab.com
Tue Feb 18 17:21:32 EST 2014

I recently duplicated a non-redundant 3BXL setup with a pair of units 
running HSRP+RSTP.   Everything appears to work great, except for almost 
100Mbps / 20kpps of flooding.   I took a span of the traffic and it's 
straight up random unicast traffic on all the busy VLANs.  Tried setting 
the global mac aging on both to 14400 with little to no observed change.

Other than the flooding, there doesn't seem to be any routing/switching 

The copp policy, and traffic/mac table sizes are pretty much identical 
to the non-HSRP setup from before that didn't have any issues.

CPU usage is quite low.

Could this be a copp problem or something else I'm overlooking with 


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