Cat2950 Buffer Misses - Guidelines?

[dave.ellis]

I've been trialling some new software recently which regularly alerts me to the fact that many of my switches (2950s, 3500xls etc)are getting a high proportion of buffer misses (all sizes of buffer) compared to hits. For example the miss rate often goes up to 12% or so. None of the misses are due to no memory. It's great to be told about this but how do I know whether I should do anything about this. ie is it normal to expect this kind of level on a regular basis. Are there any guidelines on what sort of miss rates are reasonable ? I don't want to waste time trying to fix it if it isn't a problem. Thanks

[smahbub]

The buffer misses and trims likely indicate buffered broadcast traffic that may not get processed by the switch, but if the majority of the traffic on the customer's network is extraneous broadcast traffic, the switch probably doesn't need to hear it anyway.

Consistently, when heavy or bursty broadcast traffic is sent to the 2950, the same buffer misses and trims are seen, traffic passing through the switch at this time is unaffected our best bet is to take a closer look at the trends and broadcast percentages seen in the sniffer traces and determine whether this traffic is normal or things need to be released.