[arin-ppml] Rationale for /22

William Herrin bill at herrin.us
Thu Jul 30 17:48:06 EDT 2009

On Thu, Jul 30, 2009 at 1:56 PM, Leo Bicknell<bicknell at ufp.org> wrote:
> I think many folks miss the most important item though when considering
> the effects of minimum allocation size, or other polices that are
> likely to affect the size of the global table.

Hi Leo,

If I may draw it back to the question I started with: Can you offer a
well grounded reason to believe that changing the minimum allocation
size for *multihomed* systems is likely to affect the size of the
global table?

The only one I've been able to come up with goes something along the
lines of, "If we reduce the minimum allocation size, more folks will
multihome yielding more table consumption." That seems pretty weak in
light of NRPM

A couple of folks have said something along the lines of "you can
aggregate mutlihomed users anyway," but as you know those arguments
turn on some basic misunderstandings about how BGP works.

Another suggested that the minimums allow a convenient place to filter
when trying to preserve older hardware a little longer, but as you
know such filtering is just as functional (or dysfunctional) at any
prefix size, not just the RIR minimums. At most, the RIR minimums give
the BOFH somewhere to [disingenuously] point his finger when his
customers complain.

Like you, still others have pointed out that if every single-homed
user announced a route the Internet would collapse. That is not in
dispute. RIRs assigning addresses to single-homed users would increase
the route table size. PI for single-homed users is frankly a
discussion for another era. In BGP/IPv4, that ship has sailed. My
question covers only multihomed uses, and my real focus is multivendor
multihomed uses where route aggregation is impractical regardless of
who assigns the addresses.

So can you offer a justifiable reason to believe that changing the RIR
minimum allocation size for *multihomed* systems is likely to affect
the size of the global table?


William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004

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