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Re: default route on other subnet

        Hello.  So unless I'm really not understanding what's going on, I
wouldn't expect your example to work.  A bridge is not a router.  What I
mean by that is that a bridge cannot move a packet from one IP subnet, i.e. to another,  Instead, what I suggest is something

1.  Define an interface on the bridge on Dom0 and give it an IP address of

2.  On your guest domU, give its interface an address of

3.  On the guest domU, set the default route to

4.  If you want the guest domU to manage a 10.2.2.x subnet inside itself, 
I find hard to imagine, but hey, I'm not really that creative, define  a
new interface in the domU and give it an address of

5.  Then, set a route on Dom0 like:
route add

        That will cause the Dom0 to send packets destined for the 10.2.2.x
subnet to the DomU on

Hope that helps.

On Sep 30,  9:23pm, Pierre-Philipp Braun wrote:
} Subject: Re: default route on other subnet
} Quoting Brian Buhrow 30/09/2011 17:24,
} >     Ok.  Is it possible to give the NetBSD DomU, under the Linux Dom0 a
} > public address which attaches to a bridge which connects to the real
} > ethernet of the Linux external interface?  If so, then you could use pf or
} > ipfilter on that NetBSD DomU to do  the filtering you want.  Or, perhaps, I
} > don't understand your problem?
} Yes that's the bridge config which I'm actually trying out but the 
} gateway, although it's reachable from the network interface hence the 
} bridge (there's even a rule to accept my guest's mac address), doesn't 
} respond.  That's the problem.  There's some arp issues involved and I 
} don't know where they lie-in in exactly.  But my situation proves the 
} limits of linux/netbsd compatibility in a xen environment on linux dom0s 
} (which I quite high, I must say, everything's fine apart ffs log and this).
} As an example, in a bridge configuration, say I've got on 
} the dom0 and I want on the guest.  And the gateway is 
}  The procedure from the networking FAQ should do but I get
} xx:xx:xx:xx:xx:xx tried to overwrite permanent arp info for
} repeatedly.  Where xx:xx... is the mac address of the gateway.
} On the dom0, peth0 and eth0 (the name of the bridge in fact) both have 
} network interface's mac address.  peth0 has no IP while the bridge, 
} eth0, gets the dom0 IP.  The vifs get FE:FF:FF:FF:FF:FF and no IP.
} Thanks
} Pierre-Philipp
>-- End of excerpt from Pierre-Philipp Braun

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