MAC flapping [closed]

asked 2014-10-07 14:21:57 -0500

Leon gravatar image

updated 2014-11-06 17:53:50 -0500

we have a network node setup with etherchannel bonding 2 x 1 Gbps connects to a 3750e switch. Recently we've noticed that in the switch logs, we are seeing MAC address flapping between two port-channels , Po1 and Po4. Po1 is the switch uplink to a core switch, and Po4 is openstack network node.

 Oct  1 16:00:16.135 EDT: %SW_MATM-4-MACFLAP_NOTIF: Host xxxx.xxxx.fd90 in vlan 1 is flapping between port Po1 and port Po4

Oddly enough, that the mac address x.fd90 is actually our core switch. How is the openstack network node presenting a core switch MAC address to an edge switch ?? We are also seeing several other edge switches MAC address being presented by the openstack network node.

It appears that the openstack server is sending PIM and IGMP queries, which I don't think it should be doing. This makes the switch treating it as an multicast router, so that the switch will be forwarding any multicast report(request) to the openstack server and thus the openstack attached switch p

any ideas ?

Thanks! Leon

edit: issue resolved. We have the server configured with active/active instead of bonding ( server admin said that there is an issue with bonding on the server end ). So regardless, we configured etherchannel on the switch to utilize both links. This setup caused loops on the network, nothing major happened yet but glad we had it sorted out. Now we need to find out how to bond correctly on the network node...

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Closed for the following reason the question is answered, right answer was accepted by Leon
close date 2014-11-06 17:54:18.932940


you should edit your question to add more details instead of using comments.

smaffulli gravatar imagesmaffulli ( 2014-10-10 05:21:37 -0500 )edit