How to test network bandwidth between two machines

http://askubuntu.com/questions/7976/how-do-you-test-the-network-speed-betwen-two-boxes

I use iperf. It's a client server arrangement in that you run it in server mode at one end and connect to its from another computer on the other side of the network.

One both machines run:

sudo apt-get install iperf

Then on Computer A (Server):

iperf -s

And on Computer B (Client):

iperf -c <address of Computer A>