FedericoCoppola wrote
I deployed a very small OpenVPN server on Ubuntu Server VM.
I need to manage less than 5 VPN (at maximum) connection that never happen in the same time.
After OpenVPN deployment I did some iperf test. I noted a very strange result
iPerf3 test from Remote PC with IP 10.8.0.3 to OpenVPN server with IP 10.8.0.1 (VPN tunnel is UP, using OpenVPN subnet IP) bandwith: 2/3 Mbit
iPerf3 test from OpenVPN server with IP 10.8.0.1 to Remote PC with IP 10.8.0.3 (VPN tunnel is UP, using OpenVPN subnet IP) bandwith: 10Mbit
I do not understand the reason that generate different bandwith result.
Iperf reverse test with openvpn generate different result.
Remote PC Internet speed is 30Mbit Download/25Mbit Upload (LTE connection)
OpenVPN server Internet speed is FTTH 1Gbit Download/300Mbit Upload
It's really hard to say. LTE connections vary, rarely meeting their stated standards IME. What do you get without the VPN? If the non-VPN speeds are close to the VPN speeds, that's the issue. Try several times.
One possible issue is that openvpn version 2.x is a single-threaded application. If that core happens to be overloaded or missing AES-NI support, it could impact bandwidth. The solution to that, DCO (data channel offload) is in the openvpn3 client already and will be in the server in version 2.6.
Hope this helps, regards, rob0
