[153793] in North American Network Operators' Group
Re: IPv6 /64 links (was Re: ipv6 book recommendations?)
daemon@ATHENA.MIT.EDU (Dave Hart)
Wed Jun 13 00:51:00 2012
In-Reply-To: <4FD815C7.2040108@necom830.hpcl.titech.ac.jp>
From: Dave Hart <davehart@gmail.com>
Date: Wed, 13 Jun 2012 04:50:30 +0000
To: Masataka Ohta <mohta@necom830.hpcl.titech.ac.jp>
Cc: nanog@nanog.org
Reply-To: davehart_gmail_exchange_tee@davehart.net
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On Wed, Jun 13, 2012 at 4:23 AM, Masataka Ohta wrote:
> I just need a UPnP capable NAT to restore the end to end
> transparency.
You're not restoring transparency, you're restoring communication
after stateful reconfiguration of the network for each service. It is
not transparent when you have to negotiate an inbound path for each
service. Even for apps that work today through local NATs, the future
is dim. Increasing use of carrier NAT will force apps to additionally
try Port Control Protocol to overcome evolving IPv4 brokenness. UPnP
is inadequate for carrier NAT due to its model assuming the NAT trusts
its clients.
When TCP headers are being rewritten, it's a strong hint that
transparency has been lost, even if some communication remains
possible.
Cheers,
Dave Hart
