[c-nsp] ICMP Packet loss

[Gert Doering]

Hi,

On Fri, Mar 23, 2007 at 06:50:52AM +0100, Ahmad Cheikh-Moussa wrote:
> the ping are sent to the router interface.
> I've got no packetloss with big packets, when I send ping
> packets from a host to another host over this line.

control-plane rate limiting?

> !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> !!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!
> !!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!
> !!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!
> !!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!
> !!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!
> !!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!
> !!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!
> !!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!
> !!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.!!!!!!

This regular pattern is *very* typical for ICMP rate limiting - either
on the to-be-pinged host, or (even more frequent :) ) on the router 
you are pinging *from*.

It's rate-limiting the ICMP responses coming back - and thus the CPU isn't
"recognizing" them -> "."

gert
-- 
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Gert Doering - Munich, Germany                             gert at greenie.muc.de
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