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Switch Connectivity Issue - Spanning Tree

Attached is a current network diagram.  The wireless point to point links between the switches are 5.8Ghz radio's.  All switches are Cisco Small Business 200 24-port POE.

I first turned up switch A, B and C but only had wireless links A and B connected.  My thought was making switch A the root bridge would allow spanning tree to disable link B once all the wireless links were up and running.  However, once I turned up wireless link C is when I started having issues. Here is a list of some of the symptoms.

1.  With all three wireless links up and running the wireless link ethernet port connected to switch B on link B shows as an alternate port and is discarding, which is what one would expect.

2.  Switch C does not seem to participate with the other switches in spanning-tree, it thinks its the root bridge even though switch A's priority is set to 0 and the other two are equally left at the default 32768.

3.  With all three links up, I cannot manage any of the devices at swtich C ( and are inexcessible to me)

4.  Restarting various wireless bridges produces varying results, but I can never accomplish what I think should be pretty straight forward in a simple network.

Am I missing something?

Thanks in advance.

New Member

Switch Connectivity Issue - Spanning Tree

Another interesting development.  I had to disable the link from switch A to switch C.  I can now access everything for management and configuration purposes.  However, I just noticed that switch B see's both A and C through LLDP and CDP, but switch A doesn't see switch B and switch C doesn't see switch B through either protocol.

New Member

Switch Connectivity Issue - Spanning Tree

Help!  Anyone?

Cisco Employee

Switch Connectivity Issue - Spanning Tree

Hi Mark,

What is the switch ports', connecting to the bridge, configuration (trunk, allowing required VLANs)? 

I'm not familiar with EZ bridge.  Do you reliably see any CDP messages or BPDU's from one switch to another (On one of the switches, mirror the port connected to the bridge and see what is recieved from the other switch using wireshark).



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