IPv6 routing /48s

Michael Sinatra michael at rancid.berkeley.edu
Wed Nov 19 22:15:55 UTC 2008

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.


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