Krzysztof Adamski | 2 Dec 00:56 1999

[quagga-users 2300] Re: Doesn't Quagga only populate the routingtable?

Is there an equivalent setting on Linux 2.4 kernel?


On Tue, 6 Jul 2004, Greg Troxel wrote:

>   You hit the nail right on the head.  It appears that IP input queue
>   drops were the problem.  The default value for
>   net.inet.ip.intr_queue_maxlen is 50.  Increasing this to 1024 (after
>   experimenting with other values) reduced the packet loss to 0% and
>   now net.inet.ip.intr_queue_drops increments only when there is a
>   large burst (which is apparently the goal).  I've had bursts as high
>   as 70000 pps in the last half hour.
> Well, it's a delay/drop tradeoff, but 50 is arguably too small for
> fast links.
>   The question remains, I guess, why is this so much different under
>   Quagga/Zebra than GateD?  (Not that it's a major problem now that I
>   can control it.)
> If you are right on the edge of handling the load, a small difference
> in performance could make a large difference in dropped packets. While
> the soft interrupt to service the input queue should run ahead of user
> programs, it may well be faster from idle rather than when running a
> process.  Or, the lack of a user process could keep the kernel code in
> the cache between packets - but really once it gets behind it should
> run constantly.
> _______________________________________________
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