[151024] in North American Network Operators' Group
RE: filtering /48 is going to be necessary
daemon@ATHENA.MIT.EDU (George Bonser)
Sat Mar 10 01:03:01 2012
From: George Bonser <gbonser@seven.com>
To: Joel jaeggli <joelja@bogus.com>
Date: Sat, 10 Mar 2012 06:02:00 +0000
In-Reply-To: <4F5AE797.6010702@bogus.com>
Cc: "nanog@nanog.org" <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
> I'll put this as bluntly and succinctly as I can because I find the LIR
> distriction arbitrary...
>=20
> I have an ipv6 direct assignment from ARIN.
I am assuming you are an enterprise in PI space and not an ISP in PA space?
=20
> It is sized to meet the needs of my enterprise consistent with needs
> for future growth number of pops, prevailing ARIN policy etc.
>=20
> Because my network is discontiguous I must announce more specific
> routes than the assignment in order to reflect the topology I have both
> in IPV4 and in IPV6.
> I fully expect (and have no evidence to the contrary) that my transit
> providers will accept the deaggreated prefixes and that their upstreams
> and peers will by-in-large do likewise.
If you are in PI space, I believe most people take down to a /48 as a /48 i=
s generally accepted to be a single "site". So let's say you were given a =
/40 and have several disconnected sites. Most people are going to accept a=
/48 from you in PI space. I would say pretty close to "everyone" is going =
to accept a /48 from PI space.
An ISP that has been given a /32 or larger allocation from PA space and mig=
ht have 10,000 customers each assigned their own /48 could instantly more t=
han double the size of the IPv6 routing table if they disaggregated that /3=
2. =20
The problem here is that each /32 is 65536 /48 networks. An even larger ne=
t, say a /30 that disaggregates due to a router configuration goof means a =
potential of a huge number of networks suddenly flooding the Internet.
