Reverse for a /23

[Kevin Darcy]

Stephen Amadei wrote:

> On Wed, 22 Dec 1999, Cricket Liu wrote:
>
> > If you want to "learn the lessons of RFC 2317," you might be
> > interested in the first sentence of its Introduction:
> >
> > "This document describes a way to do IN-ADDR.ARPA
> >  delegation on non-octet boundaries *for address spaces
> >  covering fewer than 256 addresses.*" [My emphasis.]
>
> O.K... I had heard RFC2317 was for doing reverse breaking _any_ of the
> octets... not just the last one.
>
> Then what would be done, for say a /17 reverse?  Create 32768 reverse
> files?

No, only 128 zones (0.xxx.xxx.in-addr.arpa through
127.xxx.xxx.in-addr.arpa or 128.xxx.xxx.in-addr.arpa through
255.xxx.xxx.in-addr.arpa), and only if you need all of them. The
in-addr.arpa naming hierarchy is based on octet boundaries; the only time
you need to play games with aliases is when you want to split beyond the
last octet, i.e. at /25 and beyond. Otherwise, just delegate down to the
next octet boundary -- in your example, from the /16 to the /24 boundary
-- and be happy.


- Kevin