IPv6 routing /48s

TJ trejrco at gmail.com
Wed Nov 19 22:20:25 UTC 2008

Just for the record, I like my host being the degenerate case of "6to4 site
+ site router all in one".
This makes my life much easier, as I frequently need IPv6 connectivity and
frequently have a public IP(v4) address (EVDO, FTW).

Having said that - what applies to me may well not be the common case.

(Just wanted to state this in case MS is listening and was thinking about
removing the functionality.  I think the right approach is to detect the
failure (s) when they occur, not to remove the functionality)


>-----Original Message-----
>From: Jack Bates [mailto:jbates at brightok.net]
>Sent: Wednesday, November 19, 2008 4:05 PM
>To: Nathan Ward
>Cc: nanog list
>Subject: Re: IPv6 routing /48s
>Nathan Ward wrote:
>> The problem here is XPSP2/Vista assuming that non-RFC1918 =
>> unfiltered/unNATed for the purposes of 6to4.
>> Well, deeper problem is that they're using 6to4 on an end host I
>> suppose
>> - it's supposed to be used on routers.
>While I don't doubt that the 6to4 is broken in such circumstances, how many
>IPv6 content providers are using 6to4 addressing and not 2001::
>addressing? 6to4 by default on xp and vista, in my experience, is only used
>if a) talking to another 6to4 address or b) there is no IPv4 address
>6to4 never seemed like a viable method for content providing, though its
>at the eyeball layer is somewhat iffy given that it's primary use is for
>other 6to4 addresses. If prefix policies are altered to use it for
>2001:: addressing, problems start arising quickly.
>A good example is that traceroutes through my he.net tunnel using 6to4
>source addresses do not get replies through he.net's network, presumably
>to their routers not being 6to4 aware and having no route to respond.
>Responses pick up again after picking up a network such as NTT that is 6to4
>aware. My 2001:: addressing works just fine the entire route.
>I'm sure there's quite a few networks that aren't 6to4 aware, hindering
>6to4 connectivity to non-6to4 addresses.

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