Re: A comment about RFC 3484 address selection

[Kurt Roeckx <kurt@roeckx.be>]

On Sun, Sep 30, 2007 at 09:07:16PM +0200, Florian Weimer wrote:
> * Kurt Roeckx:
> 
> > - A simular case is that you have 2 segments, 1.0.0.0/24 and 1.0.1.0/24,
> >   and you add a 1.0.0.2 and 1.0.1.2.  Now you want clients to connect
> >   to the one from it's own segment, and fall back to the other if it
> >   fails.
> >
> >   In this case rule 9 might be useful.  But I would rather see that this
> >   fall under rule 2 and/or 8, and that such address would be considered
> >   one with a site-local scope.  It could potentially also fall under
> >   rule 4.  It's also something that can perfectly be configured in the
> >   policy.
> 
> Scope is not defined for IPv4 addresses (neither in RFC 3484 or
> elsewhere), so Rule 2 and Rule 8 do not apply in this case.

rfc3484 section 3.2 has:
   IPv4 addresses are assigned scopes as follows.  IPv4 auto-
   configuration addresses [9], which have the prefix 169.254/16, are
   assigned link-local scope.  IPv4 private addresses [12], which have
   the prefixes 10/8, 172.16/12, and 192.168/16, are assigned site-local
   scope.  IPv4 loopback addresses [12, section 4.2.2.11], which have
   the prefix 127/8, are assigned link-local scope (analogously to the
   treatment of the IPv6 loopback address [11, section 4]).  Other IPv4
   addresses are assigned global scope.


Kurt