[Simh] Using TAP/TUN

[Peter Svensson]

On Tue, 6 Mar 2012, Michael Bloom wrote:

> I've started looking a little deeper,  and the first thing I found is this
> from linux-source/Documentation/networking/tuntap.txt:
> 
>    4. What is the difference between TUN driver and TAP driver?
>    TUN works with IP frames. TAP works with Ethernet frames.
> 
> So it would seem that to get the desired multi-protocol generality, one would
> want to use the TAP ioctls not the TUN ioctls that tunctl.c uses.  Meaning to
> support non IP protocols, the example in 0readme_ethernet.txt would need to
> change to use a "tapctl" program rather than the tunctl program it currently
> uses (or tunctl could be made into a more generic tuntapctl program).  Or
> perhaps it somehow works as desired right now, in spite of the available
> documentation.

Hi, 

tunctl already supprot both tun an tap interfaces. You just use the -p 
parameter. This is in fact the default as long as you do not specify -n. 

Simh already supports tap, it is what it is using. 

To get what you want, add both the external interface (that the machine 
regularly use) and the simh tap interface. Move your ip addresses from the 
physical interface to the bridge. Smile.

Peter