Re: [Qemu-devel] Making qemu use 10.0.3.x not 10.0.2.x

[Paul Brook <paul@codesourcery.com>]

On Wednesday 06 February 2008, Jamie Lokier wrote:
> Paul Brook wrote:
> > > > but make
> > > > it configurable on the command line.  That way, there are no
> > > > surprises ever.  The rare people like me with an issue can just pass
> > > > a command-line parameter in.
> > >
> > > The point I was trying to make is that qemu could easily arbitrate the
> > > guest network based on how the host is configured.  If the host has a
> > > 10.0.x.x network (and I suppose if we want to be thorough, a 10.0.x.x
> > > route), then it punts to 172.16.x.x (and does the same check) and then
> > > tries a couple of 192.168.x.x networks.
> >
> > I really dislike this kind of guesswork.  It makes it very hard to
> > debug/reproduce problems, and means you're never really sure what
> > qemu is going to do.  IMHO One of the really nice features of qemu
> > is that it is host independent.
>
> If it _doesn't_ guess, i.e. uses the fixed default of 10.0.2.x (or any
> other), then it's _not_ host independent.

Well, obviously anything that involves talking to the host or the outside 
world is never going to completely host independent.  Your case will also 
break if you run it on a machine with no internet connection.

The environment inside qemu is consistent.

If you have qemu automagically guess things then the gust OS also has to be 
capable of coping with things changing underneath it.

Paul