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3550 network crashes

I am new to cisco switching,

I have recently purchased 4 x 3550 24 PWR smi switches. i have followed the installation instructions and followed the web site manuals.

I have kept the switches out of the network for 2 weeks whilest i learn about them more.

I have recently moved the switches live and one of the switches is located in an area the has constant power failures. when that 1 switch cuts out the whole network crashes although the other three are working.

i have made a cluster of the 4 switches and made the main switch in the server room the command switch. I didnt make any vlans as yet and no other settings have really changed. so i have now removed all switches from the network again until i can get this working. I need to be able to have the network up and running if one of the switches fall out without the whole network crashing.

Please advise



Re: 3550 network crashes

Whats the topology of these switches? If there are loops in the network it may be a spanning tree issue. Make sure the switch in the server room is also the spanning tree root.

Can you duplicate the problem in your lab?

Community Member

Re: 3550 network crashes

It sounds to me like a spanning tree issue as well. One recommendation would be to have all your switch's on UPS power. It is a relativly cheap investment to protect your infastructure and save on downtime.

Community Member

Re: 3550 network crashes

I worked out the problem. It was so simple at teh end. one of the cross cables i had inplace was not crossed and it was causing a problem with the 3com switch that was on the other side of the network. it was causing all trafic to go through the one switch that i switched off. so i lost all but the servers and router.

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