Linux Ethernet Bridging - Mar 2010 - [Bridge] IP address on physcial interface instead of bridge interface?

Currently it isn't possible to to have an IP address on one of interfaces
attached to a bridge, one must always put the IP address on the bridge interface
itself.

I wonder if there is a technical reason for that? I would love to be able
to be able to chose any ONE interface attached to the bridge.
Example:
Assume br0 bridge with two interfaces attached, eth0 and eth1.
Then I would like to assign the IP address to eth0 instead of
br0. Ideally one should be able to just attach eth0 with an existing IP address
to br0.

    Jocke

On Thu, Mar 25, 2010 at 11:42 AM, Joakim Tjernlund
<joakim.tjernlund at transmode.se> wrote:
>
> Currently it isn't possible to to have an IP address on one of
interfaces
> attached to a bridge, one must always put the IP address on the bridge
interface itself.
>
> I wonder if there is a technical reason for that? I would love to be able
> to be able to chose any ONE interface attached to the bridge.
> Example:
> Assume br0 bridge with two interfaces attached, eth0 and eth1.
> Then I would like to assign the IP address to eth0 instead of
> br0. Ideally one should be able to just attach eth0 with an existing IP
address
> to br0.
Migrating existing configuration to the bridge at the time a port is
added (and back to one member when the bridge is dissolved) has been
discussed quite a bit recently, and is completely different from
trying to independently configure L3 state of bridge ports at
arbitrary times.

>
> ? ?Jocke
>
> _______________________________________________
> Bridge mailing list
> Bridge at lists.linux-foundation.org
> https://lists.linux-foundation.org/mailman/listinfo/bridge
>

Bart De Schuymer <bdschuym at pandora.be> wrote on 2010/03/28
14:48:52:
>
> Stephen Hemminger schreef:
> >
> > If you read the network receive code path in the kernel, you
> > will see that there is a special hook used. Basically,
> >
> >   if received_interface_is_part_of_bridge(incoming_interface)
> >   then process_bridged_packet(packet)
> >
> > Then bridge looks at packet and decides whether it is local or
forwarded.
> > The problem is with your application if it wants to use eth0 directly.
> >
> >
> The ebtables brouting chain was designed to enable you to do this.
Can you give me an example?

 Jocke

Joakim Tjernlund/Transmode wrote on 2010/03/28 20:27:10:
>
> Bart De Schuymer <bdschuym at pandora.be> wrote on 2010/03/28
14:48:52:
> >
> > Stephen Hemminger schreef:
> > >
> > > If you read the network receive code path in the kernel, you
> > > will see that there is a special hook used. Basically,
> > >
> > >   if received_interface_is_part_of_bridge(incoming_interface)
> > >   then process_bridged_packet(packet)
> > >
> > > Then bridge looks at packet and decides whether it is local or
forwarded.
> > > The problem is with your application if it wants to use eth0
directly.
> > >
> > >
> > The ebtables brouting chain was designed to enable you to do this.
> Can you give me an example?
Found this on the net:
ebtables -t broute -A BROUTING -p 0800  -i eth1 --ip-dst 192.168.1.16 -j DROP
ebtables -t broute -A BROUTING -p 0806  -i eth1 -d 00:06:9C:00:B2:FB -j DROP
ebtables -t broute -A BROUTING -p 0806  -i eth1 --arp-ip-dst 192.168.1.16 -j
DROP

192.168.1.16 and 00:06:9C:00:B2:FB are the IP and MAC addresses of eth1.

Then add eth1 to the bridge and it appears to be working as I want.
Are there any "gotcha's" with this method?

 Jocke

Joakim Tjernlund/Transmode wrote on 2010/03/28 21:04:11:
> Joakim Tjernlund/Transmode wrote on 2010/03/28 20:27:10:
> >
> > Bart De Schuymer <bdschuym at pandora.be> wrote on 2010/03/28
14:48:52:
> > >
> > > Stephen Hemminger schreef:
> > > >
> > > > If you read the network receive code path in the kernel, you
> > > > will see that there is a special hook used. Basically,
> > > >
> > > >   if
received_interface_is_part_of_bridge(incoming_interface)
> > > >   then process_bridged_packet(packet)
> > > >
> > > > Then bridge looks at packet and decides whether it is local
or forwarded.
> > > > The problem is with your application if it wants to use eth0
directly.
> > > >
> > > >
> > > The ebtables brouting chain was designed to enable you to do
this.
> > Can you give me an example?
>
> Found this on the net:
> ebtables -t broute -A BROUTING -p 0800  -i eth1 --ip-dst 192.168.1.16 -j
DROP
> ebtables -t broute -A BROUTING -p 0806  -i eth1 -d 00:06:9C:00:B2:FB -j
DROP
> ebtables -t broute -A BROUTING -p 0806  -i eth1 --arp-ip-dst 192.168.1.16
-j DROP
>
> 192.168.1.16 and 00:06:9C:00:B2:FB are the IP and MAC addresses of eth1.
>
> Then add eth1 to the bridge and it appears to be working as I want.
> Are there any "gotcha's" with this method?
What about other protocols such as pppoe and OSPF, will these work over eth1
too?
Are outgoing pkgs from the host bridged or just sent out over eth1?

    Jocke