iPerf is a widely used tool for network performance measurement and tuning. It is significant as a cross-platform tool that can produce standardized performance measurements for any network. Iperf has client and server functionality, and can create data streams to measure the throughput between the two ends in one or both directions. Typical iperf output contains a time-stamped report of the amount of data transferred and the throughput measured.
HOW TO INSTALL IPERF3
yum install iperf3
dnf install iperf3
sudo apt install iperf3
HOW TO USE IPERF3
iPerf must be installed on the computers at both ends of the connection you’re testing. iPerf requires two systems because one system must act as a server, while the other acts as a client. The client connects to the server you’re testing the speed of.
TCP Client & Server (Default mode test):
On the first server you plan to test, launch iPerf in server mode:
iperf3 -s ------------------------------------------------------------ Server listening on TCP port 5201 ------------------------------------------------------------
On the second server, connect to the first:
iperf3 -c 212.6.44.32 Connecting to host 212.6.44.32, port 5201 [ 5] local 77.73.67.143 port 57824 connected to 212.6.44.32 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 23.8 MBytes 200 Mbits/sec 0 1.67 MBytes [ 5] 1.00-2.00 sec 23.8 MBytes 199 Mbits/sec 0 2.84 MBytes [ 5] 2.00-3.00 sec 22.5 MBytes 189 Mbits/sec 0 3.00 MBytes [ 5] 3.00-4.00 sec 23.8 MBytes 199 Mbits/sec 0 3.00 MBytes [ 5] 4.00-5.00 sec 23.8 MBytes 199 Mbits/sec 0 3.00 MBytes [ 5] 5.00-6.00 sec 22.5 MBytes 189 Mbits/sec 0 3.00 MBytes [ 5] 6.00-7.00 sec 23.8 MBytes 199 Mbits/sec 0 3.00 MBytes [ 5] 7.00-8.00 sec 23.8 MBytes 199 Mbits/sec 0 3.00 MBytes [ 5] 8.00-9.00 sec 23.8 MBytes 199 Mbits/sec 0 3.00 MBytes [ 5] 9.00-10.00 sec 22.5 MBytes 189 Mbits/sec 0 3.00 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 234 MBytes 196 Mbits/sec 0 sender [ 5] 0.00-10.02 sec 232 MBytes 194 Mbits/sec receiver
Accepted connection from 77.73.67.143, port 57822 [ 5] local 212.6.44.32 port 5201 connected to 77.73.67.143 port 57824 [ ID] Interval Transfer Bitrate [ 5] 0.00-1.00 sec 20.5 MBytes 172 Mbits/sec [ 5] 1.00-2.00 sec 23.4 MBytes 197 Mbits/sec [ 5] 2.00-3.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 3.00-4.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 4.00-5.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 5.00-6.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 6.00-7.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 7.00-8.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 8.00-9.00 sec 23.4 MBytes 197 Mbits/sec [ 5] 9.00-10.00 sec 23.3 MBytes 196 Mbits/sec [ 5] 10.00-10.02 sec 502 KBytes 193 Mbits/sec - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate [ 5] 0.00-10.02 sec 232 MBytes 194 Mbits/sec receiver
During this test iPerf client was a sender and in the results we can see:
From client logs:
sender - is iPerf client, Upload speed from iPerf client to iPerf server is measured.
receiver - is iPerf server, Download speed on iPerf server from iPerf client is measured.
From server logs:
receiver - is iPerf server, Download speed on iPerf server from iPerf client is measured.
TCP Client & Server (Reverse mode test):
iperf3 -s ------------------------------------------------------------ Server listening on TCP port 5201 ------------------------------------------------------------
To run it in reverse mode where the server sends and the client receives, add the -R switch:
iperf3 -c 212.6.44.32 -R Connecting to host 212.6.44.32, port 5201 Reverse mode, remote host 212.6.44.32 is sending [ 5] local 77.73.67.143 port 34440 connected to 212.6.44.32 port 5201 [ ID] Interval Transfer Bitrate [ 5] 0.00-1.00 sec 21.2 MBytes 178 Mbits/sec [ 5] 1.00-2.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 2.00-3.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 3.00-4.00 sec 23.3 MBytes 195 Mbits/sec [ 5] 4.00-5.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 5.00-6.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 6.00-7.00 sec 23.3 MBytes 195 Mbits/sec [ 5] 7.00-8.00 sec 23.4 MBytes 196 Mbits/sec [ 5] 8.00-9.00 sec 23.3 MBytes 196 Mbits/sec [ 5] 9.00-10.00 sec 23.4 MBytes 196 Mbits/sec - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 234 MBytes 197 Mbits/sec 18 sender [ 5] 0.00-10.00 sec 231 MBytes 194 Mbits/sec receiver
Accepted connection from 77.73.67.143, port 34438 [ 5] local 212.6.44.32 port 5201 connected to 77.73.67.143 port 34440 [ ID] Interval Transfer Bandwidth Retr Cwnd [ 5] 0.00-1.00 sec 24.5 MBytes 205 Mbits/sec 6 675 KBytes [ 5] 1.00-2.00 sec 22.5 MBytes 189 Mbits/sec 11 699 KBytes [ 5] 2.00-3.00 sec 23.8 MBytes 199 Mbits/sec 0 724 KBytes [ 5] 3.00-4.00 sec 23.8 MBytes 199 Mbits/sec 0 748 KBytes [ 5] 4.00-5.00 sec 22.5 MBytes 189 Mbits/sec 0 772 KBytes [ 5] 5.00-6.00 sec 23.8 MBytes 199 Mbits/sec 1 795 KBytes [ 5] 6.00-7.00 sec 23.8 MBytes 199 Mbits/sec 0 816 KBytes [ 5] 7.00-8.00 sec 22.5 MBytes 189 Mbits/sec 0 839 KBytes [ 5] 8.00-9.00 sec 23.8 MBytes 199 Mbits/sec 0 860 KBytes [ 5] 9.00-10.00 sec 23.8 MBytes 199 Mbits/sec 0 880 KBytes [ 5] 10.00-10.02 sec 0.00 Bytes 0.00 bits/sec 0 880 KBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bandwidth Retr [ 5] 0.00-10.02 sec 234 MBytes 196 Mbits/sec 18 sender [ 5] 0.00-10.02 sec 0.00 Bytes 0.00 bits/sec receiver
During this test iPerf server was a sender and in the results we can see:
From client logs:
sender - is iPerf server, Upload speed from iPerf server to iPerf client is measured
receiver - is iperf client, Download speed on iPerf client from iPerf server is measured
From server logs:
sender - is iPerf server, Upload speed from iPerf server to iPerf client is measured
receiver - is iPerf client, Download speed on iPerf client from iPerf server is measured
Note that we didn't specify the port, as in this case there is iperf3 on both sides, with ports defaulting to 5201.
How to open a port:
sudo firewall-cmd --zone=public --add-port=5201/tcp
sudo ufw allow 5201
iPerf3 flags
To run it in reverse mode where the server sends and the client receives, add the -R switch.
If port 5201 is being used by another program on your server, you can specify a different port (e.g 3000) using the -p switch as shown.
You can specify the format (k, m, g for Kbits, Mbits, Gbits or K, M, G for KBytes, Mbytes, Gbytes) to report in, using the -f
To run a bi-directional test, meaning you measure bandwidth in both directions simultaneously, use the -d option.
If you want to get server results in the client output, use the --get-server-output option.
Optionally, you can run the server as a daemon, using the -D flag and write server messages to a log file.
For more information, see the iPerf3 man page.
iPerf3 Homepage: https://iperf.fr/