Stopping Spanning Tree broadcasts from a 3560 switch.

Posted on 2007-11-28
Last Modified: 2012-08-13
There is only 2 switches. Spanning tree is not configured.. but when monitoring traffic, i keep seeing these... and there are a ton of them..
79      34.081723      Cisco_1c:be:8c      Spanning-tree-(for-bridges)_00      STP      Conf. Root = 32772/00:1b:54:1c:be:80  Cost = 0  Port = 0x800c
80      36.086681      Cisco_1c:be:8c      Spanning-tree-(for-bridges)_00      STP      Conf. Root = 32772/00:1b:54:1c:be:80  Cost = 0  Port = 0x800c
95      53.814725      Cisco_1c:be:8c      Cisco_1c:be:8c      LOOP      Reply

How do i turn these off?
Question by:jaysonfranklin
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LVL 21

Expert Comment

ID: 20369449
on the particular interface type: spanning-tree bpdufilter enable
this command will disable broadcasting of bpdu packets from this interface and will filter out all incoming bpdu packets

conf t
interface gi1/1
spanning-tree bpdufilter enable

Author Comment

ID: 20369549
do I do that on all the physical interfaces or just the vlan interfaces?

Author Comment

ID: 20369570
i just did int range 0-52

im still getting this one though..

389      20.083187      Cisco_1c:be:8c      Cisco_1c:be:8c      LOOP      Reply

what is this? im assuming i need to do that for all the int's on SW2  or just doing it on the main one should be good?
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LVL 21

Accepted Solution

from_exp earned 500 total points
ID: 20369577
on all active physical interfaces
use range command
conf t
interface range gi1/1 - 10
LVL 21

Expert Comment

ID: 20369648
it looks like cisco loop detection protocol.
it should funtion
LVL 50

Expert Comment

by:Don Johnston
ID: 20369839
They appear to be BPDU's. Without seeing the complete frame it's hard to say for sure.

Spanning tree is enabled by default of all Cisco switches. I REALLY don't recommend turning it off. The BPDU's aren't consuming much bandwidth and they'll prevent a layer 2 loop if a redundant link is ever connected.

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