[124079] in North American Network Operators' Group
Re: IP4 Space
daemon@ATHENA.MIT.EDU (Nathan Ward)
Mon Mar 22 23:46:16 2010
From: Nathan Ward <nanog@daork.net>
In-Reply-To: <3B128C1B-B1AE-4927-A1CD-208A5BBDB590@academ.com>
Date: Tue, 23 Mar 2010 16:45:34 +1300
To: nanOG list <nanog@nanog.org>
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 19/03/2010, at 4:07 AM, Stan Barber wrote:
> 1. Almost all home users (not businesses) that are connected to the =
Internet today via IPv4 are behind some kind of NAT box. In some cases, =
two NATs (one provided by the home user's router and one provided by =
some kind of ISP). There is no need for this using IPv6 to communicate =
with other IPv6 sites.
There are a large number of users, here in NZ at least, but I imagine in =
other places, that have a single ethernet port "ADSL Modem" which =
terminates PPP, does IPv4 NAT, DHCP, etc. and then a "Wireless Router" =
which has its ethernet "Internet" plug connected to the "ADSL Modem", =
and does IPv4 NAT, DHCP to end hosts, etc.
This means that they have double NAT inside the home, and then in the =
future a potential third NAT. We did some looking at packets, and 17% of =
outbound packets from customers at an ISP had TTLs that indicated two L3 =
hops in the home - which for the majority of cases would mean double =
NAT.
In NZ the most popular ADSL deployment is PPPoATM, so the ADSL unit the =
ISP ships (either loaned, or included in the install cost) is an IPv4 =
router terminating a PPPoATM connection, not a bridge or anything.
--
Nathan Ward=
