[123145] in North American Network Operators' Group
Re: 6to4 on Sprint Wireless Broadband
daemon@ATHENA.MIT.EDU (Joe Abley)
Mon Mar 1 12:19:24 2010
From: Joe Abley <jabley@hopcount.ca>
In-Reply-To: <20100227151325.GB671@koltblut.setec.org>
Date: Mon, 1 Mar 2010 12:18:51 -0500
To: Izaac <izaac@setec.org>
X-SA-Exim-Mail-From: jabley@hopcount.ca
Cc: nanog@nanog.org
Errors-To: nanog-bounces+nanog.discuss=bloom-picayune.mit.edu@nanog.org
On 2010-02-27, at 10:13, Izaac wrote:
> A few months ago, is appears that Sprint started dropping 6to4
> encapsulated packets. Egress is fine. Ingress silently drops. =
Anyone
> see anything similar? Or am I the only guy crazy enough to be doing
> this sort of thing in the first place?
6to4 is a method for tunnelling v6 over v4 without =
statically-configuring endpoints. The encapsulation used is protocol-41, =
i.e. the same as "tunnel mode ipv6ip" in IOS or "interfaces ip-a/b/c" in =
JUNOS. It seems unlikely that Spring has decided to block IPv4 packets =
with protocol 41 payload.
What seems far more likely is that the relay routers used for return =
packets from the hosts you are trying to talk to are hitting a broken =
6to4 relay router, and hence the return traffic is being (from your =
perspective) silently discarded.
Joe=
