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Bridging loop with a linksys unmanaged switch

my network completely crashed down due to a bridgning loop.

Somebody connected a linksys unmanaged switch to an access port. The access port has portfast configured and bpduguard enabled.

At first the port fastly turn in an err-disabled state because of the bpduguard function. after a while the ports tries many times to recover and always come back to an err-disable state.

at a certain point the linksys switch probably collapses and stops sending many packets included BPDU Packets.

at this point the port in my cisco catalyst recovers from the err-disable (bpduguard) state and turn into a forwarding state--> then catastrophe!!! the whole LAN is setteled down and I have to switch off all my catalysts and then power then one by one to find the looped port.

Isn't there any way to prevent this without recurring to port-secure functions?

I tried to disable bpduguard automatic recovering and it seems to work fine: the port is put into a permanent err-disabled state. but i don't know if there may be other unknown issues.

Would spanning tree loopguard default help in any manner?

thanks

Johnny

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Bridging loop with a linksys unmanaged switch

Disabling the err-disabled automatic recovery, it will not do any wrong other then increase your workload.

For loopguard, this is for root or alternate port, not designated. Last I checked, loopguard and portfast are not to be configured on the same port.

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