Is the layer 3 traffic multicast? Your indication of HA makes me suspect it is and perhaps you have a multicast snooping/filtering on the Cisco or some other related limiter setting.
Just a total guess without any configs or other pertinent data. -----Original Message----- From: Ivan [cisco-...@itpro.co.nz] Received: Saturday, 28 Jun 2014, 5:10PM To: cisco-nsp [cisco-nsp@puck.nether.net] Subject: Re: [c-nsp] Cisco 4900M and Layer2 Broadcasts Sorry to respond to my own post but I have some further thoughts that may be useful. The traffic ends up being broadcast at layer 2 (dest MAC address ff:ff:ff:ff:ff:ff) but the IPv4 payload is generally unicast. So I am thinking perhaps the 4900M could be "getting upset" with these packets. Not really expecting the 4900M to look higher than layer 2 of these packets though as vlan does not have SVI. Ivan On 28/Jun/2014 10:17 p.m., Ivan wrote: > I am hoping someone may have come across an issue I am seeing on a Cisco > 4900M running 15.1(2)SG3. > > I have a device connected to an interface sending traffic from it's own > MAC address to MAC address ff:ff:ff:ff:ff:ff. When the layer 3 protocol > is IPv6 I see this going out other port in the same vlan as the source - > all good. When the layer 3 protocol is IPv4 the frames seem to go into > a black hole - very bad. I have confirmed all this with packet captures. > > I have poked around but cam find any indication of the issue. I will be > logging a TAC case in the next day or two for this but would be > interested to hear if anyone else has seen this. > > Thanks > > Ivan > > PS. Not really looking to get into the details of the connected devices > etc - just some HA type traffic using layer 2 over a vlan. _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/ _______________________________________________ cisco-nsp mailing list cisco-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/