Life with Linux

One way of testing the speed of your network connection is to use netcat and pv (adapted from a post by Shawn Willden)

On Ubuntu/Debian you can install netcat and pv by doing:


sudo apt-get install pv
sudo apt-get install netcat (could be already installed)


After the installation, on machine A run:

netcat -ulp 5000 > /dev/null

This sets up a UDP listener on port 5000 and directs the output to /dev/null. Use UDP for this to avoid the overhead of TCP.

On machine B, run:

pv < /dev/zero | nc -u <ip_or_hostname_of_machine_A> 5000

where "ip_or_hostname_of_machine_A" is the hostname or IP address of the listening machine A.

This will start a stream of zero-filled packets across the network to machine A, and pv will print out an ongoing report on the speed at which the zeros are flowing.

Let it run for a while and watch the performance.

For a Gigabit network the numbers you're getting should be over 100 MB/s. The theoretical limit on a Gig-E network is around 119 MBps.

Do the same thing without the "-u" options to test TCP performance. It'll be lower, but should still be knocking on 100 MBps. To get it closer to the UDP performance, you may want to look into turning on jumbo frames.