Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

HOSTFLAPPING problem in 4506 l3

*Oct 20 06:38:54: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 7 is f

lapping between port Gi4/1 and port Gi4/6

reply ASAP


Re: HOSTFLAPPING problem in 4506 l3

I saw this when we had server with teamed NIC connected to two different could be also incorrectly configured sever (teaming, etherchanel).. I would suggest to find machine connected to this ports and check configuration


Re: HOSTFLAPPING problem in 4506 l3

It could mean someone has physically looped those 2 ports together or possible that someone is roaming between 2 ap's .

New Member

Re: HOSTFLAPPING problem in 4506 l3

thanks for repply

both are trunk port, one l3 is root bridge

we are facing this problem only vlan 7 and vlan 1

gi4/1 is connected between two L3

Gi4/6 is a L2 switch for user connectivity.

All uplink are Trunk Port

waiting for reply

Re: HOSTFLAPPING problem in 4506 l3

this could be issue with duplicate MAC ID on your network,someone might be assigned MAC id

manually to the NICs.

try to find out that device.

you can shutdown one of the port and try to locate the other one by

sh mac-address-table |include MAC ID