Re: Re: icmp/ping implementation in linux

[sreangsu acharyya <sreangsua@xxxxxxxxxxxxxxxxxxxxx>]

On Tue, 20 Mar 2001, Nandu wrote:

> Well I tried that once on dialup with -s 1500 and I could see a huge burst of 
> outgoing traffic on kpppload. But I can't talk interms of packets. Never 

exactly the point. Maybe the kernel is fragmenting the packets to a size
of 576. If that is whats happening, the quick and dirty script below will
not be giving interpretable results. ( The intent is to calculate the
throughput at different mtu values ... the starting mtu should be higher
than 1500)

host=
mtu=300
while [ $mtu -le 1500 ]
do
 num=`ping -s $mtu -c 15 $host|grep round|cut -f 4 -d " "|cut -f 2 -d "/"`
 mtu=`expr $mtu + 50`
 tput=`echo "scale=3;$num/$mtu" | bc`
 echo " $mtu $tput">output.txt
done