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GBIC on catalyst 3550 switch

The GBIC interface is transmiting and receiving high brocast and multicast. The link goes on and off in an average interval of 45mins.


Re: GBIC on catalyst 3550 switch


These numbers in the controller bus should be zero for normal Gbic. If these number go over 0, take a look at rx values means receive traffic is causing the problem. Or the tx value. It means that interface is not able to transmit the packets. In this case you see all the values are receive. It means that it can be huge broadcast or over whelming interface. Also look at the buffer issue. Do show buffer and see if we need buffer tuning. Packets dropped because the interface hardware buffers ran low on internal buffers (FIFO buffers). While this may help another possible cause is a broadcast storm. To isolate the broadcast storm you can either put a sniffer on the line to find out where the broadcasts are coming from or you can pull the vlan segments out of the switch, clear counters, and then plug them in one by one monitoring the queues on the router to see which segment is causing the broadcasts.

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