[350] in North American Network Operators' Group
Re: CIDR FAQ
daemon@ATHENA.MIT.EDU (Dorian Rysling Kim)
Fri Aug 18 01:43:42 1995
Date: Fri, 18 Aug 1995 01:38:39 -0400 (EDT)
From: Dorian Rysling Kim <dorian@CIC.Net>
To: Hank Nussbacher <HANK@taunivm.tau.ac.il>
cc: nanog@merit.edu
In-Reply-To: <199508180529.BAA10411@merit.edu>
On Fri, 18 Aug 1995, Hank Nussbacher wrote:
> >Ah. here is the rub. When you ISP buddies come back, you should ask
> >them to return the origianal /22 for a /20. That way, the total size
> >of the routing system stays the same!
>
> Great idea. Know ANYONE who does that? The best I can do is give them a
> /20 (in addition to the original /22) if their growth warrants it.
Sure. We are starting to do that. We are trying to put into practice
following allocation strategy:
1) when allocating, leave enough holes so the address space can be grown
within that /16. For example, leaving next three spaces unallocated when
assigning /24. We try to guess at who'll be growing and how much. It's
not perfect, but it's better than nothing.
2) if the site returns /24, or /23, or /22, and we can't grow that
address block, we try to see if we can recycle the old block and assign a
new larger block.
This way, if our internal routing changes, and our old aggregation scheme
breaks, we keep renumbering to the minimum.
-dorian
______________________________________________________________________________
Dorian Kim Email: dorian@cic.net 2901 Hubbard Drive
Network Engineer Phone: (313)998-6976 Ann Arbor MI 48105
CICNet Network Systems Fax: (313)998-6105 http://www.cic.net/~dorian
