Re: Virtual circuits

Martin Josefsson
Mon, 03 Dec 2001 14:12:27 -0000

On Mon, 3 Dec 2001, bert hubert wrote:

> On Mon, Dec 03, 2001 at 11:01:09AM +0100, M.F. PSIkappa wrote:
>
> > I''m interesting about this, I know that in FreeBSD
it''s posible via
> > netgraph but I didn''t see any usable solutions for linux.
> > I know about Frame Diverter but it''s not suitable for my
purpose.
>
> This is not what these Virtual Circuits are - the VCs I mention are ATM
> vc''s, not ''bridging tunnels''.
>
> > How to sent _everything_ (e.g. arp) from client1 to client1_router?
> > I cant use any tunnel.
> > It''s posible with linux ?
>
> Well, you can use a tunnel, it''s just that you want a
''bridging tunnel'',
> that appears by magic so to speak. Basically you are then a two-port
> repeater with a long bit in the middle.
>
> Now, is this possible? I think it is, I''m just not entire sure
how.
>
> Perhaps a proxy-arping pseudo bridge does what you want? In that case ARPs
> are not transmitted over your tunnel, but your tunnel device reacts to ARP
> requests for hosts it knows about on the other side.
>
> If you want a real bridge, you should find a way to create a
''virtual
> interface'' that lives on the remote host, and run a bridge between
your
> regular interface and the ''virtual long distance'' one.
>
> Perhaps this is possible.

Yes it is, by using CIPE and the normal ethernet bridge you can do exactly
this. CIPE is an encrypted tunnel that creates a virtual ethernet
interface that can be used for bridging.

http://sites.inka.de/bigred/devel/cipe.html

"it is even possible to run an Ethernet bridge over CIPE"

It says it only works with the bridge in kernel 2.4 or using a patched 2.2

Hope it helps.

/Martin

Never argue with an idiot. They drag you down to their level, then beat you with
experience.