Re: CIDR FAQ

[Elise Gerich <epg () MERIT EDU>]

i believe that the ripe ncc tried this allocation idea initially,
but discovered that the ncc ended up with bits of address space
here and there which was just not the right size, so the ncc
would end up allocating more non-contiguous space anyway.
with that experience the ncc has abandoned that practice.

perhaps, daniel, geert-jan  or someone else from the ripe ncc
could speak about their experience.
        --elise

> Dorian Rysling Kim writes:
>
> 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