iptraf is great to quickly monitor network usage. Just don’t forget Heisenberg’s uncertainty principle (or, to be more technically correct, the observer effect) – using iptraf over a proxied ssh connection adds about 6.6 kbps of usage just for the tool used to measure usage. Fun fun! :>
Here’s a script that you can run to measure bandwidth in the background, removing some of the overhead of trying to visually display in realtime the very thing you’re measuring:
#!/bin/bash
if [ -e /var/log/iptraf/bandwidth.txt ]
then
rm /var/log/iptraf/bandwidth.txt
fi
export SAMPLETIME=1
export SLEEPTIME=62
iptraf -B -t $SAMPLETIME -i all -d eth0 -L bandwidth.txt
sleep $SLEEPTIME
cat /var/log/iptraf/bandwidth.txt|grep kbits
