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Question on Header Buffers.....

The following is taken from "show buff" on a 1751's FastEthernet interface, running at 100mbit, FDX:


Header pools:

Header buffers, 0 bytes (total 179, permanent 128, peak 179 @ 2w6d):

51 in free list (10 min, 512 max allowed)

165 hits, 846 misses, 0 trims, 51 created

805 failures (0 no memory)

128 max cache size, 128 in cache

107207692 hits in cache, 845 misses in cache


I notice that there are more buffers in existance, than what are in the 'perminent' setting, does this indicate an improper setting? I thought that buffer tweaking had the goal of minimizing / erradicating buffer drops&misses. Thoughts? Suggestions?



Re: Question on Header Buffers.....

165 hits + 846 misses seems to be approximately equal to 805 faileures. I think your buffer tweaking is not working well. Both hits and misses should be more than failures. In you case the misses is very high. You can revert it to the default setting.

New Member

Re: Question on Header Buffers.....

I haven't touched the Header Buffers setting (I don't know how) The only thing I've changed, is the small, mid, large, very-large buffer settings to get the system buffers to stop logging tons of misses & drops. Hopefully this isn't a trade, where I can have a high number of drops in either the system buffer, or header buffer, and can't get rid of the drops totally...



Re: Question on Header Buffers.....

I dont think misses are an issue. It just means that the pool had to be expanded, but thats how its designed to work. The pool can grow during peak times and shrink (trims) later. When I questioned this some time back I was told that it does not mean any data was dropped or even delayed. I cant see it now but I think your display said that the peak was hit 2 weeks ago. That shows that the pool does not have to be set that high permanently.

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