Hi, I was trying to have a SSH tunnel with at least 150Mbps/s in both directions. I have a laptop computer under Ubuntu 20.04.2 and a remote server also under Ubuntu 20.04.2. I measured the speed of my internet connection with Iperf3 and without SSH Tunnel it is OK. $> iperf3 -c <SERVER_IP> -p 7503 - 500 Mbits/sec laptop -> server $> iperf3 -c <SERVER_IP> -p 7503 -R - 927 Mbits/sec laptop <- server Then I open a SSH Tunnel: laptop -> server $> ssh -L 7503:127.0.0.1:7503 root@my_server Doing the iperf3 test again $> iperf3 -c 127.0.0.1 -p 7503 - 13.6 Mbits/sec $> iperf3 -c 127.0.0.1 -p 7503 -R - 672 Mbits/sec And now the speed is terrible from my laptop to the server. In the iperf console this looks like this [ ID] Interval Transfer Bitrate Retr Cwnd [ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 2 1023 KBytes [ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 1 639 KBytes [ 5] 2.00-3.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes [ 5] 3.00-4.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes [ 5] 4.00-5.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes [ 5] 5.00-6.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes [ 5] 6.00-7.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes [ 5] 7.00-8.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes [ 5] 8.00-9.00 sec 0.00 Bytes 0.00 bits/sec 0 639 KBytes [ 5] 9.00-10.00 sec 1.25 MBytes 10.5 Mbits/sec 0 639 KBytes During some seconds there is no Bitrate at all :(. I understand that the SSH tunnel will add some overhead and I will lose around 10/20% of Bandwidth but this looks like a huge drop. Do you have any idea what can create this behavior? Thanks for your help, Clement _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
