tun/tap on ubuntu

**sesquipedality** · January 22nd, 2005

Does the standard ubuntu kernel have support for the tun/tap device driver? If not, how does one go about adding support for it (i.e. compiling a compatible module or whatever else is required)? Thanks.

**trapik** · January 26th, 2005

yes /sbin/modprobe tun

**sesquipedality** · January 30th, 2005

Thank you. I really didn't expect it to be that simple.

**Happy** · April 4th, 2005

I've just spent the last several hours trying to get tun to work...
it just doesn't like me.
I've added the 'tun' module using modprobe and that's about it
whenever I try 'ifconfig tun0 10.0.0.1 up' or similar I get this result:
SIOCSIFADDR: No such device
tun0: ERROR while getting interface flags: No such device
tun0: ERROR while getting interface flags: No such device

I've created the /dev/net/tun node and checked it's privileges and all that jazz but still no love!
ifconfig -a comes up empty for the tun0 interface...
any ideas?
(i've installed the vtun package via synaptic was that the correct one?)

**suoko** · January 10th, 2006

I have the same problem using kernel 2.6.12-10-686 but I don't have any problems with latest dapper kernel.
Question: is it a problem related to the kernel?

**GTvulse** · January 10th, 2006

Originally Posted by Happy

I've just spent the last several hours trying to get tun to work...
it just doesn't like me.
I've added the 'tun' module using modprobe and that's about it
whenever I try 'ifconfig tun0 10.0.0.1 up' or similar I get this result:
SIOCSIFADDR: No such device
tun0: ERROR while getting interface flags: No such device
tun0: ERROR while getting interface flags: No such device

I've created the /dev/net/tun node and checked it's privileges and all that jazz but still no love!
ifconfig -a comes up empty for the tun0 interface...
any ideas?
(i've installed the vtun package via synaptic was that the correct one?)

Have you created a virtual interface bridge? You need the userspace utilities contained in the vtun package (that's in the Universe repository).

**cylon359** · January 11th, 2006

You can also create a persistent tunnel with openvpn...

sudo openvpn --mktun --dev tun0

**GTvulse** · January 11th, 2006

There is also a tunctl utility in User Mode Linux (that hasn't worked for me, YMMV). You can download the source code from the project's CVS repository: http://www.user-mode-linux.org/cvs/t....c?sortby=date.

**GTvulse** · January 13th, 2006

Originally Posted by dradul

There is also a tunctl utility in User Mode Linux (that hasn't worked for me, YMMV). You can download the source code from the project's CVS repository: http://www.user-mode-linux.org/cvs/t....c?sortby=date.

I can now say I have successfully used tunctl to set up a PPPoE (RFC2516) connection using the eciadsl drivers (big change in my ISPs a day after I posted the above).

Now I'm using a PPPoE connection emulated over a persistent virtual ethernet TAP created with tunctl and controled with the eciadsl drivers. I tried with openvn at first but I then realized that it made the TAP device dependent on the openvpn daemon. Using tunctl is easier. You can either install uml-utilities available in the universe repository, or compile tunctl.c[1] and type a simple command[2].

[1] gcc -O2 -s -o tunctl tunctl.c

[2] sudo ./tunctl -u root tap0