[OLSR-users] olsrd with 2 networks

Bernd Petrovitsch (spam-protected)
Wed Feb 8 15:02:00 CET 2006

On Wed, 2006-02-08 at 14:44 +0100, Kosta Welke wrote:
> Bernd Petrovitsch wrote:
> > On Wed, 2006-02-08 at 09:26 +0100, Kosta Welke wrote:
> > That's actually one feature (IMHO) that you don't need NAT at all (which
> > is the reason not mentioning it): Give one interface on each box a
> > public IP address (if you really want to see it on the Internet and vice
> > versa) and give all others private IP addresses (no IMHO we don't really
> > have a shortage of IPv4 addresses but it is not trivial to get some from
> > RIPE).
> Seems like a good idea to me. The non-trivial part is tell olsrd which 
> interface is the 'primary' one, because this is the one that is routable 
> to the outside world.

In a classic mesh box:
Shouldn't that come via olsr and manifests itself as a default route?
In a "i'm hooked up on an ordinary ISP" scenario:
Shouldn't that come via olsr and manifests itself as a default route
which has a significant higher metric than my usual default route (i.e.
the one via the ISP)?

> I think what Sven-Ola Tuecke was saying is that if you have /32 
> addresses and a default route (independent of your olsr network) and 
> want to send to an olsr node to which you dont have a route, it gets 
> send to the default route, which usually is an ISP.

Ah, of course.
In such a situation you want some simple iptables rules which simply
kill these packets (or you masquerade it and it won't be delivered at
the other end which delivers logically the same result but produces
superflous network traffic).

> This should not be a problem as the netmask doesnt really matter when 
> you use the -b option.

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