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From: Joe Greco <jgreco@brasil.moneng.mei.com>
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Subject: Re: tun0 device
To: SimsS@Infi.Net (Steve Sims)
Date: Tue, 17 Sep 1996 11:38:44 -0500 (CDT)
Cc: hackers@FreeBSD.org
In-Reply-To: <199609161836.OAA27880@mh004.infi.net> from "Steve Sims" at Sep 16, 96 02:36:17 pm
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> Where's the seminal reference on the tunnel device? =20
> 
> `apropos tunnel` yields nada.  Ditto for `man tun`.
> 
> I don't have a *recent* handbook, but the one I have mentions it only in =
> passing.
> 
> Muchas Gracias in advance....

RTFS :-)

It's actually quite trivial (at least from my experience) and quite nice:

The tun device looks and acts like any other Point to Point network
interface.  Configure it as such.

Open the corresponding /dev/tunX device and you can read packets that the
system sent with your program, and/or you can inject packets back into the
system's IP processing.

It is fairly straightforward from what little I've played with it.

... JG