[Lxc-users] [Spam-Wahrscheinlichkeit=45] lxcbr0 MAC addr issue

[Hans Feldt]

> -----Original Message-----
> From: Jäkel, Guido [mailto:G.Jaekel at dnb.de]
> Sent: den 5 juni 2013 09:26
> To: Hans Feldt; 'lxc-users at lists.sourceforge.net'
> Subject: RE: [Spam-Wahrscheinlichkeit=45][Lxc-users] lxcbr0 MAC addr issue
> 
> Dear Hans,
> 
> this is a FAQ here but -- as you already found -- not basically caused by LXC.
> The software bridge will always choose the lowest MAC of the attached
> devices or hold an explicit assigned (from the set of currently assigned
> devices) as long as possible. In your case you either may set the MAC of the
> outgoing NIC or set the MAC of the veth's from a range which is above
> common hardware. There are more or less reserved ranges used for this by
> us here and in similar projects.

Setting it to the MAC of the outgoing NIC is that safe or can it cause any problems?

The MACs of the veth's are automatically set by lxc so what do you mean with "set the MAC of the veth's from a range"?

Those "reserved ranges", do you have a pointer?

I just thought it would be nice if lxc at boot could set this up automagically for all of us...

Thanks a lot,
Hans

> 
> Guido
> 
> >-----Original Message-----
> >From: Hans Feldt [mailto:hans.feldt at ericsson.com]
> >Sent: Wednesday, June 05, 2013 8:23 AM
> >To: lxc-users at lists.sourceforge.net
> >Subject: [Spam-Wahrscheinlichkeit=45][Lxc-users] lxcbr0 MAC addr issue
> >
> >
> >It is a fact that the bridge takes the lowest MAC address from the
> >attached ports for the host port. See for example
> >http://backreference.org/2010/07/28/linux-bridge-mac-addresses-and-
> dyna
> >mic-ports/
> >
> >Thus if a container is restarted, the host port can potentially change
> >its MAC address and containers will have a stale ARP cache. This of course
> causes problem for communication container->host.
> >
> >Tested the workaround mentioned in the link but then I got problem with
> >network manager on a later Ubuntu version. Then I tried using a dummy
> container and reusing its MAC addr for the host port. Works but...
> >
> >Now my question, could not lxc (at boot) setup a fixed MAC addr for the
> host port?
> >
> >Thanks,
> >Hans