Help with udptunnel

Hi everyone,

I'm trying to setup an UDP over TCP tunnel with the udptunnel package. First, let me show you my current setup:

My goal is to first learn how udptunnel works and then later set up a PXE environment using these tunnels. But in this case I just need to understand how udptunnel works.

To begin with, I'm trying a simple approach, using TFTP, and trying to redirect UDP port 2002 to UDP port 69 of FREEBNT.

The documentation I found about udptunnel is little. I found this link which is down now but I found it in Following this documentation, I tried to guess a little bit what is each parameter/value/etc. But I didn't succeed.
Let me show you how I did this time:

I installed udptunnel package and kmod-udptunnel4 in both FREEBNTUNNEL and TPLINK.

Then I created an SSH tunnel like this:

root@FREEBNTUNNEL:~# ssh -l root -p 22 -i /root/.ssh/KeyB_priv -L *:30330:

then, I executed these 2 commands in TP_LINK (first) and FREEBNTUNNEL (second):

root@TPLINK:~# udptunnel -s 30330
root@FREEBNTUNNEL:~# udptunnel -c


root@FREEBNTUNNEL:~# udptunnel -c

Then, from my computer TACENS, I tried to GET a TFTP file from the tunnel. For this I opened TFTPD64 and used the TFTP client section, and pointed to port 2002. (I used the port 2002 not to interfere with the TFTP server of FREEBNTUNNEL which is usually active).

I made sure that the same thing was working (directly, without the tunnel), pointing to port 69, and all other settings were the same. And it actually works.

Then, can anybody tell what is my error in this, or any clue about how to solve this thing?

Thanks in advance

Take a look:

Hi @AndrewZ ,

I have examined the post you linked, tried to understand the command structure, but I didn't succeed in my example.

What I did is, first obviously the tunnel, then in the server side:

root@TPLINK:~# udptunnel -s invalid port number
root@TPLINK:~# udptunnel -s 30330

and in client side:

root@FREEBNTUNNEL:~# udptunnel -c 2002
setup_tcp_client: connect: Operation timed out

Do you have any idea on why I'm not succeeding yet?

And do you have a link to any udptunnel documentation for the OpenWRT's version of the command?


Hi again,
I came up with the idea of trying it simpler; I didn't do the tunnel this time, and tried attacking the TCP port of TPLINK directly. These are the commands:

root@TPLINK:~# udptunnel -s 30330

and then client side:

root@FREEBNTUNNEL:~# udptunnel -c 2002
setup_tcp_client: connect: Operation timed out

Then I tried to TFTP to server but didn't succeed.

That was 3 years ago... As far as I remember, I had to use that version because the version provided by OpenWrt did not meet my needs.

Ok thanks anyway