[133333] in North American Network Operators' Group
Start accepting longer prefixes as IPv4 depletes?
daemon@ATHENA.MIT.EDU (Iljitsch van Beijnum)
Wed Dec 8 13:31:06 2010
From: Iljitsch van Beijnum <iljitsch@muada.com>
Date: Wed, 8 Dec 2010 19:30:52 +0100
To: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
(My apologies if this has been discussed before, I haven't been keeping =
up with NANOG as well as I should lately.)
As the IPv4 address space depletes, various types of use that requires =
IPv4 addresses will get harder. In some cases, this is unavoidable: if =
you want to connect a million broadband users you need a million =
addresses. But for hosting activities you don't need that much space. In =
fact, often people have to be very creative to qualify for a /24 (/20 =
even in ARIN-land?) just so they have a large enough assignment that =
they can announce it in BGP and expect it to be reachable. But you =
really don't need a /20 or even a /24 to host websites or the like.
Why not move away from that /24 requirement and start allowing /28s or a =
prefix length like that in the global routing table? This will allow =
content people to stay on IPv4 longer with fewer compromises, so we =
don't have to start thinking about NAT46 solutions in the near future. =
(NAT46 is really best avoided.)
There are two issues:
1. Growth of the routing table. My answer to this is: although a smaller =
table would be good, we've been living with 16% or so growth for a =
decade before the IPv4 crunch, if going to < /28 instead of < /24 allows =
this growth to continue some more years there is no additional harm. And =
there is no evidence that /28s will create more growth than =
unconstrained /24s like we had before the IPv4 crunch.
2. People who think it's neat to deaggregate their /16 into 256 /24 will =
now go for 4096 /28s. To avoid this, the new /28s should come from =
separate ranges to be identified by the RIRs. So /28 would only be =
allowed for this new space that is given out as /28, not for anything =
that already exists and was thus given out as much bigger blocks.
Thoughts?
I'm hoping to get some modest support here before jumping into the RIR =
policy shark tanks.=
