[arin-ppml] Merits of "returning" part of a class C

John Curran jcurran at istaff.org
Fri Aug 29 11:52:48 EDT 2008

On Aug 29, 2008, at 10:58 AM, Jeremy H. Griffith wrote:
> Personally, I don't meet the current ARIN criteria for need
> because I cannot justify half of a /22.  I'm not an LIR.  But
> I certainly can justify need for *some* PI space.  When this
> debate began, I seriously considered whether I could return
> part of my /24 to help; I could live with a /28.  But my main
> upstream dissuaded me on the grounds that nothing below a /24
> was routable, and therefore I would accomplish nothing.  I
> suspect that anyone with a legacy Class C is in the same boat.

Quite likely, unless our expectations of what is routable changes
significantly in the near future.

I'll note that at some point your ISP may change its tune on the
merits of having you squeeze down into a /26, particularly since
the remainder would be already routed by the ISP, and useful for
connecting additional IPv4 customers in about 3 years...   This
wouldn't be "returning" per se, but a transfer per relaxed policy
in a post-depletion world, if such is available.


p.s.  The decision to take an ISP up on such an offer is rather
       interesting; you might want service level assurances in
       addition any transfer incentive (since one's ability to
       leave without renumbering could be quite limited given
       your resulting block size and prevailing routing policy)

More information about the ARIN-PPML mailing list