[188966] in North American Network Operators' Group
Re: IPv6 prefix from T-Mobile USA used but not announced in BGP
daemon@ATHENA.MIT.EDU (Aaron Hopkins)
Wed Apr 27 16:16:32 2016
X-Original-To: nanog@nanog.org
Date: Wed, 27 Apr 2016 13:16:28 -0700 (PDT)
From: Aaron Hopkins <lists@die.net>
To: Baptiste Jonglez <baptiste@bitsofnetworks.org>
In-Reply-To: <20160427193420.GA27020@lud.polynome.dn42>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
On Wed, 27 Apr 2016, Baptiste Jonglez wrote:
> While doing statistics on the participants of a public DHT, I was
> surprised to see some IP addresses that are not present in the DFZ:
I believe those are used by T-mobile's 464XLAT (RFC 6877) implementation.
Recent Android on T-mobile is IPv6-only and has no ability to connect to
raw IPv4 addresses. T-mobile's DNS servers are only asked by these devices
to translate hostnames to IPv6 addresses. If they can't find an IPv6
address, they will look up the IPv4 address for a hostname, and pack it into
the bottom 32 bits of an IPv6 address that routes to a IPv6-to-IPv4 NAT
device.
> 2607:7700:0:25::4e00:605b
4e00:605b -> 78.0.96.91
-- Aaron
