Re: Setting routes for routed setup

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Sat, Aug 08, 2009 at 11:46:40PM +1000, Christian Lerrahn wrote:
> Hi,
> I'm still trying to get a routed setup to work (the data centre
> infrastructure does not let me do bridged). The problem I currently
> have is that I'm unsure how to set up the routes. The Linux scripts
> would set up routes like
> 
> ip route add 1.2.3.4 dev xvif1.0 src 9.8.7.6
> 
> where 1.2.3.4 is the address of the domU and 9.8.7.6 the address of the
> dom0. On Linux the dom0 would sit in a netmask 255.255.255.255 and have
> the main IP address assigned to both the physical interface and
> xvif1.0. Then the host routes between the physical interface and
> xvif1.0 make sense. Should this be done on NetBSD, too? Or is there a
> better way of handling this?

This is a strange setup. It looks like linux uses the xvif interface like
a point to point interface, while it emulates an ethernet one.

I'm not sure how this would work on NetBSD. A better way would probably
to have all the domUs in the same netmask, and assing the dom0 one IP
address in this netmask on a virtual interface (e.g. a tap0 created
for this purpose), distinct from the IP/netmask of the hardware interface.
Then you bridge all the domUs and tap0 in the same ethernet domain,
and route between tap0 and the hardware interface.

Other setups involving ipf/ipnat are probably possible, but that would
require some experiments.

-- 
Manuel Bouyer <bouyer%antioche.eu.org@localhost>
     NetBSD: 26 ans d'experience feront toujours la difference
--