OpenVPN Support Forum

Hi,

I have an OpenVPN server that uses the UDP protocol and a client that connected to it.
I wonder what happens if the client sends TCP packets to the server?
The TCP packets will be warrped with UDP because the initial connection between the 2 was UDP?
And if so do the TCP ack system will work? If the server won't get the TCP packet it will be retransmitted by the client?

Thanks in advance,

Zed.

Hopefully i understand your question correctly.

There are 2 ways to answer your question:
1) Your openvpn-server is listening on some UDP port, say 1194. TCP packets send to port 1194 (that is, external ip-address of the server and TCP port 1194) are rejected by the ip-stack of the server: There's nobody listeing on TCP-1194. No wrapping or whatsoever is done.

2) Inside the tunnel is a different situation. I wrote an explaination some time ago how that works.

Hope this helps

Yes it helps. Thank you!