Go Back   The macosxhints Forums > OS X Help Requests > UNIX - Newcomers

Thread Tools Rate Thread Display Modes
Old 04-03-2012, 10:45 PM   #1
Posts: n/a
Tunneling UDP over SSH

It's hard to find a suitable forum for this question, but I suppose this should be one of the more appropriate ones. Mind that this is probably a pretty 'advanced' question

I have this situation: a game server (Enemy Territory) is running inside an isolated network which only has a few access points to the outside world by means of SSH. Someone outside this network wants to play on this game server. If the game would be using TCP for network connections, it would be quite simple: setting up an SSH tunnel should do the trick. However, like most FPS games, ET uses UDP, on port 27960. SSH does not allow tunneling UDP traffic.
However, there are ways to convert (or 'bridge') UDP traffic to TCP traffic and vice versa. For instance, "netcat" on Linux/UNIX can do this. So I tried the following.

'client' is the computer outside the protected network.
'intermediate' is the computer inside the network, which allows SSH access from outside.
'server' is the computer inside the network, on which the ET server runs.
In short, I set up an UDP->TCP bridge on 'client', tunnel the TCP traffic through an SSH tunnel to 'intermediate', where it's converted back to UDP and sent to 'server'. bubble games

In more detail: the first thing I do is setting up an SSH tunnel from client to intermediate, on some arbitrary TCP port:

ssh -L 5901: intermediate

Next, I set up a TCP->UDP bridge on intermediate, which directs the UDP traffic to server:

netcat -u -L server:27960 -t -p 5901

Finally, I set up an UDP->TCP bridge on client:

netcat -t -L -u -p 27960

So now I would theoretically just need to start ET on the client an connect to However, this doesn't work, it keeps waiting for a connection. Yet, if I connect to UDP port 27960 on the client with netcat, I can talk to the ET server, so the UDP tunnel seems to be working. Does anyone have any idea why it doesn't work with ET itself?
  Reply With Quote
Old 07-22-2013, 05:00 PM   #2
Registered User
Join Date: Jul 2013
Posts: 1
This should help...

Check out the thread at hintsforumsDOTmacworldDOTcomSLASHarchiveSLASHindex.phpSLASHt-101635.html
turningjapanese is offline   Reply With Quote

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

All times are GMT -5. The time now is 09:18 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Site design © IDG Consumer & SMB; individuals retain copyright of their postings
but consent to the possible use of their material in other areas of IDG Consumer & SMB.