Re:Tinc VPN: Secure Private Network Between Hosts
by ptman on Wednesday February 07, 2018 @03:21PM
(#16327652)
By SSH tunneling, I assume you mean SSH port forwarding (-R/-L). Recent OpenSSH also has Tunnel (-w) which provides an IP-level VPN, in which case it does do TCP over TCP.
Re:Tinc VPN: Secure Private Network Between Hosts
by loeg on Wednesday February 07, 2018 @03:25PM
(#16327678)
Yes, or even SOCKS mode (-D).
SSH tunnels are not VPN tunnels. SSH will act as the endpoint for your TCP application and only tunnel the application payload over SSH (TCP). On the other side a new TCP session will be opened over which that payload is sent. So you never do TCP over TCP.
It's more so a proxy than a tunnel and that avoids the real issue, which is nested congestion control. In addition SSH should also be able to do so with less overhead (in bytes) than a VPN (which need to forward the IP and TCP header intact), but I don't know how well SSH takes advantage of that.
SSH tunneling can outperform OpenVPN running in TCP or UDP mode.