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Unexpected BPDU received. Port has been Disabled

rfasenmyer
Level 1
Level 1

For some reason I get random reports in Cisco Network Assistant indicating the following:

"Unexpected BPDU received. Port has been Disabled"

Today I saimotaneously received this alert for 5 ports on 3 different switches. All of these ports had Cisco Aironet 1200 series access points connected to them. The only thing I do to get them back online is to manually disable the port and then manually enable the port. I'm baffled as to what can be causing this. Have any of you seen this type of problem before.

Thanks,

Ryan Fasenmyer

Technology Coordinator

Cathedral Preparatory School

3 Replies 3

amritpatek
Level 6
Level 6

The port where you are seeing this issue is receiving BPDU?s and in that specific port you must have spanning-tree bpduguard enable that is why the port has been disabled.Refer URL

http://www.cisco.com/univercd/cc/td/doc/product/lan/cat3750/12225see/cr/cli3.htm#wp1945530

Yes, probably you have some users bridging between multiple connections (wireless and wired for instance, seems like windows can do this easily). If Bpduguard was configured on the interface, it will detect a bridged bpdu and will disable the port. That's a protective measure you can disable, or you can have the port re-enabled automatically after a configurable period of time.

ftallet,

I checked the switch port paramaters (GBIC master switch and the switch that the access point is connected to) and found the BPDU Gard to not be enabled. Do you know of anything else that could cause this problem?

All our clients connect through our access points so I don't know how they could bridge a connection unless they were plugged into the wired LAN and had wireless on at the same time. The locations where the access points are failing do not have wired LAN connections available.

Can you tell me where I can find the setting to make a port automatically re-enable itself after a period of time. I wish I knew what was cuasing the problem but I don't have time to figure it out now, so I'm willing to just let it automatically heal itself.

Thanks,

Ryan

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