[c-nsp] SUP2T Ignoring ARP response... 12.2(50)SY3

Peter Kranz pkranz at unwiredltd.com
Thu Apr 4 18:40:24 EDT 2013

Figured this out.. I'll explain it here in case someone else runs into this
in the future..


By default cisco uses the same MAC address for every VLAN configured on a


The downstream switches were getting confused by this (customer was
combining the two vlans together rather than keeping them seperate) and not
sending ARP responses back to the correct port..


Using mac-address xxxx.yyyy.zzzz to alter the mac address of one of the two
vlans on the 6500 immediately resolved the problem.




Peter Kranz
 <http://www.unwiredltd.com/> www.UnwiredLtd.com
 <mailto:pkranz at unwiredltd.com> pkranz at unwiredltd.com


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