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Hostflapping and multicast addresses on a cisco 4506 switch

Tags: hostflapping, cisco, host
I have a 4506 switch configured and it's giving the followiing error messages

Nov 3 14:47:59: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:91:46:66:01 in
vlan 901 is

Now I have bpdufilters on the give port numbers specified in the error messages withe loopguard, pvst,uplink and backbone fast configured. When I do a sh mac-address-table it gives me mulitcast entries with a number of ports...How can I fix this issue.  
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Question Stats
Zone: Networking
Question Asked By: ritru
Solution Provided By: donjohnston
Participating Experts: 2
Solution Grade: B
Views: 82
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Comment by microIT
I have the same issue.  When you run show spanning-tree what am I looking for?
 
 
Comment by donjohnston
Towards the bottom will be a list of ports. The will see "FWD" (forwarding) or "BLK" (blocking).

There should only be one path between any two devices.
 
 
Comment by microIT
donjohnston, thanks for the response.  in my case i actually did find a switch that had a fiber trunk and a ethernet trunk to the same core switch.  the ethernet trunk was in a blocking state upon sh spantree.  once in a blocking state does that mean it would have been causing hostflapping or a loop?  or does that mean STP shut it down?
 
 
Comment by donjohnston
Neither. A port is placed in blocking mode because spanning-tree detected a loop. No (non-spanning-tree) frames are allowed in or out of a blocked port.
 
 
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