Notes on iperf
(14 August 2012)
Available on rpmforge.
Basic throughput testing, TCP:
- run the server
# iperf -s
- run the client
# iperf -c 10.0.0.22
------------------------------------------------------------
Client connecting to 10.0.0.22, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 3] local 10.0.0.251 port 46617 connected with 10.0.0.22 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 1.10 GBytes 944 Mbits/sec
It is popular to use iperf in udp mode to detect dropped packets. To do this:
- run the server in udp mode:
# iperf -s -u
- run the client in udp mode, rate-limited to 100 Mb/s:
# iperf -c 10.0.0.22 -u -b 100m -i 1
Beware that when using UDP, the client will send at either its local maximum rate or the defined rate -- even if the server can't deal with that volume of data, and what the server can't deal with will be reported as lost packets. This is not necessarily a problem with your network. (UDP packets get lost. That's life.)