[Fedora-xen] Xen network bridge questions (using network configuration tools provided by distribution)

[Pasi Kärkkäinen]

On Mon, Feb 26, 2007 at 03:13:04PM +0100, Bertho Stultiens wrote:
> Pasi Kärkkäinen wrote:
> [snip]
> > 1. Changes the MAC-address of peth0 to FE:FF:FF:FF:FF:FF. If I have another
> > physical interface, peth1, can it have the same MAC address, or does it have 
> > to be different? 
> 
> In principle, all unicast MACs in a broadcast domain have to be unique.
> Each vlan is a broadcast domain, so that is fine. However, the kernel
> has a slightly different view of the interfaces and I an not sure that
> it can keep everything properly isolated. The FE:FF..FF addresses are
> fake anyway and should be local only. There is then the STP problems you
> can run into depending on whether you have all isolated STP instances
> for each vlan/interface.
> 
> To make a long story short :), use unique MACs to avoid problems. You
> can use them f.ex. from the 00:01:01, 10:00:00, ac:de:48... (and there
> are more private MAC pools defined; see
> http://standards.ieee.org/regauth/oui/oui.txt and look for PRIVATE).
> 
> [do not use MAC addresses with an odd numbered high octet; these are
> reserved for multicast/broadcast]
> 

OK. Thanks.

Because peth* and xenbr* have NOARP, it should be ok to use fake
MAC-addresses.. for example:

peth0 FE:FF:FF:FF:FF:00
peth1 FE:FF:FF:FF:FF:01

etc.

Or should I use some of the PRIVATE address ranges from that doc? 


> 
> > 2. Sets peth0 to NOARP (disables ARP). Why is this? Is it a requirement? 
> > 3. Sets xenbr0 to NOARP. Same question goes for this.
> 
> The NOARP is because you do not want the interfaces to answer to arp
> requests. Neither interface has an IP address assigned, so they are to
> be local only and their MAC should not propagate. It is a requirement so
> far as to have them shut up...
>

OK. 
 
> 
> > I have working setup with FC6 network scripts/tools, but I'd like to make
> > sure I do the correct things.
> 
> If you also could post your resulting scripts or make a micro-howto,
> that would be great too. Polishing can be done on the list I guess.
> 

I'll do it after I've tested them properly :)

-- Pasi