Operational Issues with

That is a good point, but you are talking about a periodic notification
when new blocks are allocated. Michael is talking about an automated


of all unallocated blocks.

I'm talking first of all, about a directory listing all the unallocated
space that people can query. Secondly, I'm suggesting that this same set
of data could be published by ARIN using BGP to make it easier for people
to monitor changes.

If we were to invert this and say that ARIN
will provide a list of all blocks that are allocated to it, then that


be worth doing.

I specifically suggested that ARIN provide a list of unallocated blocks
because otherwise everyone else has to suck down the entire database of
allocated blocks and invert it themselves. If they screw up their
inversion algorithm that creates further problems.

In an ideal world, IANA would provide a top-level LDAP directory of the
entire IPv4 address space with referrals for each large allocation to the
RIR LDAP servers just like the DNS delegates a domain to other DNS
servers. But it is just as workable for the 4 RIRs to work out some other
way of synchronizing the top level of the IPv4 address space and for all 4
of them to publish the entire data set in their local (topologically
speaking) servers.

However, I get back to my original question. For people who insist on
filtering unallocated address space, is it too much to ask that they


subscribe to NANOG, or potentially subscribe to an RIR-specific
announce-only mailing list for such things?

Yes. This is the 21st century. Mailing lists are a 19th century technology
(memorandums) dressed up with a bit of 20th century technology. We can do
better. If we can create routing protocols that dynamically distribute
routing topology data, then we can surely come up with an automated way of
distributing the IPv4 allocation data. People who are scared of automation
can insert the human being inside their own domains of control. But let's
use some network protocols for the core distribution of the data.

It seems really silly to me
for the registries to spew a mailing to their entire contact database


to reach a handful of people who actually do route filtering.

Yes, spewing out email to solve a simple database synchronization problem
seems counter-productive to me.
Even a plain ASCII text file mirrored with rsync polling would be a vast
improvement over email. But LDAP is proving to be the direction that the
world is moving in for this type of directory service so why not leverage
the tools and expertise that are available out there?

-- Michael Dillon

lynx -dump http://www.iana.org/assignments/ipv4-address-space | grep "IANA - Reserved"