I’ve expanded my home network with new switch and I wanted to test the connection speed between different computers. At first, I ran rsync, but I’ve quickly realised it’s limited by source/destination read/write speeds.
I found better way of measuring connection speed using netcat:

# start listening on one computer ie 10.0.0.5
nc -vvlnp 12345 < /dev/null

# start broadcasting ~100MB from another computer
dd if=/dev/zero bs=1M count=100 | nc -vvn 10.0.0.5 12345
## 104857600 bytes (105 MB) copied, 8.89602 s, 11.8 MB/s

You can use more sophisticated tools for the same purpose ie. iperf:

# install on both boxes
sudo apt-get install iperf

# start server in one computer
iperf -s

# measure connection speed from client(s)
iperf -c server_IP
##[  5]  0.0-10.0 sec   112 MBytes  94.1 Mbits/sec

Inspired by AskUbuntu.