# Test localhost bandwidth with iperf3 https://github.com/esnet/iperf ## launch a server process ``` iperf3 -s ``` ## run client against server ``` ➜ 05-2021-07 ~/bin/iperf3/bin/iperf3 -c localhost -f M Connecting to host localhost, port 5201 [ 5] local 127.0.0.1 port 43600 connected to 127.0.0.1 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 6.70 GBytes 6862 MBytes/sec 0 1.69 MBytes [ 5] 1.00-2.00 sec 6.82 GBytes 6982 MBytes/sec 0 1.75 MBytes [ 5] 2.00-3.00 sec 6.90 GBytes 7069 MBytes/sec 0 1.87 MBytes [ 5] 3.00-4.00 sec 6.59 GBytes 6748 MBytes/sec 0 2.06 MBytes [ 5] 4.00-5.00 sec 6.60 GBytes 6756 MBytes/sec 0 2.06 MBytes [ 5] 5.00-6.00 sec 6.88 GBytes 7040 MBytes/sec 0 3.12 MBytes [ 5] 6.00-7.00 sec 6.95 GBytes 7116 MBytes/sec 0 3.12 MBytes [ 5] 7.00-8.00 sec 6.76 GBytes 6918 MBytes/sec 0 3.12 MBytes [ 5] 8.00-9.00 sec 6.86 GBytes 7026 MBytes/sec 0 3.12 MBytes [ 5] 9.00-10.00 sec 6.81 GBytes 6975 MBytes/sec 0 3.12 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 67.9 GBytes 6949 MBytes/sec 0 sender [ 5] 0.00-10.00 sec 67.9 GBytes 6949 MBytes/sec receiver iperf Done. ``` # IPv4 vs IPv6 ``` ➜ 05-2021-07 ~/bin/iperf3/bin/iperf3 -c localhost -f M -4 Connecting to host localhost, port 5201 [ 5] local 127.0.0.1 port 43630 connected to 127.0.0.1 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 6.68 GBytes 6844 MBytes/sec 0 1.31 MBytes [ 5] 1.00-2.00 sec 6.79 GBytes 6950 MBytes/sec 0 1.50 MBytes [ 5] 2.00-3.00 sec 6.80 GBytes 6963 MBytes/sec 0 1.62 MBytes [ 5] 3.00-4.00 sec 6.85 GBytes 7019 MBytes/sec 0 1.62 MBytes [ 5] 4.00-5.00 sec 6.76 GBytes 6918 MBytes/sec 0 2.06 MBytes [ 5] 5.00-6.00 sec 6.64 GBytes 6801 MBytes/sec 0 2.06 MBytes [ 5] 6.00-7.00 sec 6.75 GBytes 6910 MBytes/sec 0 3.12 MBytes [ 5] 7.00-8.00 sec 6.73 GBytes 6896 MBytes/sec 0 3.12 MBytes [ 5] 8.00-9.00 sec 6.71 GBytes 6872 MBytes/sec 0 3.12 MBytes [ 5] 9.00-10.00 sec 6.79 GBytes 6955 MBytes/sec 0 3.12 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 67.5 GBytes 6913 MBytes/sec 0 sender [ 5] 0.00-10.00 sec 67.5 GBytes 6913 MBytes/sec receiver iperf Done. ➜ 05-2021-07 ~/bin/iperf3/bin/iperf3 -c localhost -f M -6 Connecting to host localhost, port 5201 [ 5] local ::1 port 36244 connected to ::1 port 5201 [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 7.28 GBytes 7457 MBytes/sec 0 1.44 MBytes [ 5] 1.00-2.00 sec 7.36 GBytes 7532 MBytes/sec 0 1.44 MBytes [ 5] 2.00-3.00 sec 7.34 GBytes 7518 MBytes/sec 0 1.44 MBytes [ 5] 3.00-4.00 sec 7.47 GBytes 7649 MBytes/sec 0 1.44 MBytes [ 5] 4.00-5.00 sec 7.38 GBytes 7559 MBytes/sec 0 2.56 MBytes [ 5] 5.00-6.00 sec 7.64 GBytes 7821 MBytes/sec 0 2.93 MBytes [ 5] 6.00-7.00 sec 7.10 GBytes 7270 MBytes/sec 0 2.93 MBytes [ 5] 7.00-8.00 sec 5.34 GBytes 5467 MBytes/sec 0 2.93 MBytes [ 5] 8.00-9.00 sec 5.35 GBytes 5475 MBytes/sec 0 2.93 MBytes [ 5] 9.00-10.00 sec 5.25 GBytes 5373 MBytes/sec 0 4.43 MBytes - - - - - - - - - - - - - - - - - - - - - - - - - [ ID] Interval Transfer Bitrate Retr [ 5] 0.00-10.00 sec 67.5 GBytes 6912 MBytes/sec 0 sender [ 5] 0.00-10.00 sec 67.5 GBytes 6912 MBytes/sec receiver iperf Done. ```