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3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

This is just an attempt of mine to reach out to the Cisco Networking community to see if others have been experiencing this particular problem. I've recently purchased (2) 48 port versions of the 3550-EMI. Units were inter-connected via fiber Gigabit Ethernet ports creating a physical loop (Switch A G01=>Switch B G02 & Switch A G02=>Switch B G01). The switches fail detect loop, both assume root bridge roles, and VLAN1 (only VLAN1!!!) goes into loop. Other non-native create VLANs behave properly (i.e. detect loop, determine root bridge, and block one port in physical loop). VLAN1 will go into a loop straight out of the box with no special configs.

7 REPLIES
Bronze

Re: 3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

Please post the sh ver and sh run -

If the you know the config is good, so please open the TAC case for further investigation.

New Member

Re: 3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

I have experienced the same problem, but had to get around the issue by configuring some other switches to get the job done that evening. I am going to that customer site tomorrow (20th August 2002 @ 09.00 BST) and will be trying the 3550 equipment again. The 3550 G12 switch that I had problems with was running 12.1.9.EA1 IOS. I will get back to you soon. Please update me if you have any other information.

Cisco Employee

Re: 3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

Known issue, currently working on a software solution. Please open a TAC case for more details.

New Member

Re: 3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

All,

Thanks for the responses. A TAC case has been opened for this issue and has been opened for a couple of weeks now. Current status is awaiting fix from Cisco Development.

Andrew,

Let me know if you have any luck with your second attempt with the 3550 12G. I've tested with 12.1-8.EA1b - 12.1-9.EA1c. I'll post a reply with Cisco's fix as soon as I get one.

Cisco Employee

Re: 3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

New Member

Re: 3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

Prashanth Krishnappa ,

I couldn't find the Bug ID and the link provided does not direct you to a valid link. Is there accessible page with thie Bug info?

Bronze

Re: 3550-48 EMI Corrupt BPDU Causing VLAN1 Loop

Hope this Field Notice links helps you

http://www.cisco.com/warp/public/770/fn20553.shtml

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