Re: Bridging eth0/br0 & NetworkManager - can they coexist?

[Steve Dowe <sd@warpuniversal.co.uk>]

On 29/06/12 15:34, Camaleón wrote:
> 
>> If I edit /etc/NetworkManager/NetworkManager.conf and change
>> 
>> [ifupdown] managed=false
>> 
>> to
>> 
>> [ifupdown] managed=true
>> 
>> then eth0 and br0 both pick up the same IP address.
> 
> Mmm... and what's what you want to bridge? Remember that any bridge 
> needs at least two end points.

My intention is allow my ethernet interface to be allocated as many IPs
on my local network as necessary to service the virtual machines I'm
running.  The "bridge", in this case, is a virtual-to-physical one.

>> This is my current /etc/network/interfaces:
>> 
>> # The loopback network interface 
>> auto lo br0
>> iface lo inet  loopback
>> 
>> # bridging iface br0 
>> inet dhcp
>>   bridge_ports eth0
>>   bridge_stp off
>>   bridge_maxwait 0 
>>   bridge_fd 0
>> 
>> 
>> I must be missing something simple here.  Could anyone point me in 
>> the right direction please?  Has anyone got a working config?
> 
> There are some bridging samples here:
> 
> http://wiki.debian.org/BridgeNetworkConnections#Configuring_bridging_in_.2BAC8-etc.2BAC8-network.2BAC8-interfaces

Thanks. I did look at those.  And by following that configuration:

 # Set up interfaces manually, avoiding conflicts with, e.g., network
manager
 iface eth0 inet manual

 iface eth1 inet manual

 # Bridge setup
 iface br0 inet dhcp
        bridge_ports eth0

... Network Manager cannot control eth0.  Under "Wired Networks" it
reports "Device not managed".

Besides, the comment in that configuration is "# Set up interfaces
manually, avoiding conflicts with, e.g., network manager" - so it's
clearly acknowledge here that bridging does indeed conflict with network
manager, and I shouldn't expect it to work using that example.

> But shouldn't be better to use the same networking method (ifup or 
> N-M but not a mix of them) to configure the interfaces (eth0 and 
> br0)? :-?

Ok, so I'm getting used to the Debian way of doing things, having come
from another distro.  I assumed I /was/ using the N-M way of doing
things, editing a N-M config file.  But, I glean from your comment that
there is overlap here.

When I keep the above settings in /etc/network/interfaces and change
/etc/NetworkManager/NetworkManager.conf, from

[ifupdown] managed=false

to

[ifupdown] managed=true

then I can control eth0 through Network Manager, and I'm back at square
one - both eth0 and br0 get the same IP address, and routing breaks.

I believe harmony is possible between NM and br0 - I'm just unsure of
the approach in Debian.


-- 
Steve Dowe

Warp Universal Limited
http://warp2.me/sd