STP Loop

Unanswered Question
May 6th, 2008
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05:39:42: %C4K_EBM-4-HOSTFLAPPING: Host 02:01:00:00:00:00 in vlan 1 is flapping between port Gi2/7 and port Gi2/14,where Gi2/7 and Gi2/14 were connected to two servers.both are in Vlan1.We are using PVST in our LAN.why this problem occurs?

Any help can be appreciated



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Overall Rating: 3.5 (2 ratings)
bvsnarayana03 Tue, 05/06/2008 - 22:53
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Yes its a STP loop. You need to identify the culprit causing the loop.

Check with the command "sh spanning-tree root"

to see if the root for vlan 1 has changed.

bava_ccna Wed, 05/07/2008 - 02:21
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I found that the root for vlan 1 is not changed and there is no loop also.still the problem exists

Francois Tallet Wed, 05/07/2008 - 10:47
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It's likely to be a duplicate mac address in your network. The mac address you mentioned seems to be locally administered. So it's probably been generated by an application or a device. Try to find out where the entries are leading to in order to find the culprit(s).




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