Comment 3 for bug 865515

Dave Walker writes ("[Bug 865515] Re: virtual machines should not have nat on servers"):
> @Ian, If i understand the bug report correctly, this would seem to be a
> generic bug regarding the default networking option setup as part of
> libvirt. If this is the case, I agree it's not a great ideal for
> servers - but also not an unreasonable default for the platform as a
> whole use case.

I agree with this. But the default should be different for servers
and desktops/laptops.

> I haven't checked for other virtulisation methods, but I imagine it is
> similar. It is easy enough to provide a chosen networking model, so I'm
> not fully convinced this is a valid bug.

The existence of virbr0 convinces the Xen startup script, in the
default configuration, not to do its own networking arrangements.
Instead, since there is already a bridge, it causes all the VMs to use
it, on the principle that if there is a bridge it should probably be
used.

Ian.