RE: IPv6 routing /48s

["TJ" <trejrco () gmail com>]

Yes, always worth reminding people:
        2000::/3 is the currently active "Global Unicast" pool ... and that
doesn't mean native IPv6

        (2002::/16 = 6to4, 2001::/32 = Teredo ... ISATAP may be in play, and
not discretely indicated in prefix side of address
                ... and non-auto tunnels cold be mentioned here as well,
using global-scope prefixes )


Back to the topic at hand, and in the subject line, global routing of
arbitrary /48s is far from guaranteed.
        /32 is the default cutoff  (routing for /35s probably pretty
reliable as well)
        Up to /48s for Critical Infra / Micro-Allocations and PI-designated
blocks
... anything else AFAIK is quite possibly troublesome today.

/TJ


> -----Original Message-----
> From: Michael Sinatra [mailto:michael () rancid berkeley edu]
> Sent: Wednesday, November 19, 2008 4:16 PM
> To: Jack Bates
> Cc: nanog list
> Subject: Re: IPv6 routing /48s
>
> On 11/19/08 14:05, Jack Bates wrote:
> > 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?
>
> [other references to 2001:: addressing snipped]
>
> I hope I am not being toooo picky here, and I realize this is not part of
> your main point...
>
> If your reference to 2001:: addressing simply means "non-tunneled, globally
> routable IPv6 addressing," then I suppose it is okay.  But please note that
> there is now a lot of native (non-tunneled), globally routable IPv6
> addressing that is outside of 2001::/16.  ARIN, for example, is allocating
> blocks out of 2607::/16 and there are quite a large number of prefixes
> elsewhere in the designated globally-routable
> 2000::/3 that are *not* 6to4 addresses.
>
> The reason I bring this up is that I have already seen certain
applications,
> such as one for registering AAAA records for DNS servers in a certain TLD,
> that don't allow anything other than 2001::/16.
> (Fortunately that application was fixed quickly when those responsible were
> notified.)  Just making sure others aren't careening toward making the same
> mistake.
>
> michael