CIDR FAQ

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1

>Does that mean that all the internet registries no longer allocate
>/24 (or longer) prefixes that have nothing to do with the actual
>Internet topology (these prefixes aka "portable addresses") ? Perhaps
>folks from various Internet registries would be able to answer this
>question.

I assign /22s to ISPs. When they use them up I give them another /22.
Private companies that show a need for a /24 are assigned a /24.

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.

--
--bill

Hank

2

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