How many IPv6 prefixes should you have (Was: IPv6)

Jeroen Massar jeroen at
Fri Nov 19 09:58:33 CST 2010

On 2010-11-19 16:35, Antonio Querubin wrote:
> On Fri, 19 Nov 2010, Jeroen Massar wrote:
>> What now is more disturbing is that there appears to be a couple of
>> prefixes out there which are not in the ARIN registry anymore which are
>> still being used (Hexago/Gogo6/Freenet6/nameoftheday's 2001:5c0::/32 is
>> an exemplary one) but also 2001:1890::/32 for AT&T worldservices,
> In whois they're really a /29 but nothing prevents them from advertising
> individual /32 at different points around the net.

That explains that one at least, as it seems they upgraded themselves
out of a /32 to a /29 on 2010-10-01, seems they didn't come around
actually announcing that space yet though.

Now how shall I make GRH believe that the /32 was there once, being
announced for 7 years, but the /29 isn't yet, as stating the /29 is
announced since then is not right and tossing that information out would
not be entirely correct either...

Same goes for Rackspace it seems who are now a /30, they are at least
announcing the aggregate. Adobe also did a /48 -> /45 upgrade but are
still just announcing their old /48, same for PCH and Tellme.

The Hexago prefix though is completely missing from whois and I am
really wondering what is up with that as that prefix is quite well used
one would think. Hope somebody sorts that one out.

As for the subject of advertising more specifics... what if eg DTAG or
France Telecom decided to start announcing every separate /32 out of
their /19, that would be 8k extra routes each and the world is larger
than that thus those 300k routes in IPv6 can easily be done.

Of course, as there are a couple of RIRs who are doling out multiple
disjunct prefixes to ISPs already and various ISPs are going to all of
the RIRs for a prefix per country in some cases, not much that can be
done about that kind of swamping I guess..... thus better start coming
up with some good hardware folks that can handle copious amounts of very
long routes ;)


More information about the NANOG mailing list