Iperf bandwidth performance measurement

The tool is nice for those don't have chance to work with expensive tools from Spirent, Adtech. This I heard from 6200networks blog .

Iperf was developed by NLANR/DAST as a modern alternative for measuring maximum TCP and UDP bandwidth performance. Iperf allows the tuning of various parameters and UDP characteristics. Iperf reports bandwidth, delay jitter, datagram loss.

VMware workstation with vmnet devices

I found vmware workstation on udev based linux kernel host, that I had to run vmware-config.pl every reboot. That is because udev being a dynamic system, nodes are wiped and recreated in /dev every system rebooted. That is quite annoying when we need guest OS run as the service starts.

Add the following just under the start) line in /etc/init.d/vmware

====================================================
start)
# Start insert
if [ ! -e "/dev/vmmon" ]; then
mknod /dev/vmmon c 10 165
chmod 600 /dev/vmmon
fi
for a in `seq 0 9`; do
if [ ! -e "/dev/vmnet$a" ]; then
mknod /dev/vmnet$a c 119 $a
chmod 600 /dev/vmnet$a
fi
done
# End insert
if [ -e "$vmware_etc_dir"/not_configured ]; then
====================================================

Which recreates the nodes that are required. Remember need to re-run vmware-config.pl after a kernel upgrade.

Lastly, run vmware-netifup -d /var/run/vmnet$a /dev/vmnet$a vmnet$a to start vmnet network interface