[arin-ppml] ULA-C

Fred Baker fred at cisco.com
Wed Mar 31 20:46:21 EDT 2010

well, question. Do you need whois and all that for a local address? We don't use them for RFC 1918 addresses...

If they were global addresses, I'd be right there with you. But a ULA is used by your favorite IT department and is not normally shared with very many other organizations. It seems like the response to "whois" should be "your IT department".

On the other hand, I could imagine an allocation "policy" that consists of a web page (not my idea originally, it comes from Brian Carpenter). The web page has some variation on a counter, perhaps using a pseudo-random number generator or a cyclic feedback shift register to spread the numbers all over. When a site accesses the web page, they get a prefix, and the next person that accesses the web page gets the "next" prefix. Next question is who runs the web page; could be IANA, your favorite RIR, or anyone else the community deemed suitable. Along with that, I could imagine the person allocating the prefix having to provide some information, and some checks and balances to limit the probability of issues. The checks and balances would require discussion. They might include a name, address, and email address.

On Mar 31, 2010, at 5:29 PM, Scott Leibrand wrote:

> On Wed 3/31/2010 5:16 PM, Fred Baker wrote:
>> Dumb question.
>> The complaint with ULAs as presently formulated is that there is a non-zero probability of them colliding.
>> If you give a prefix to your favorite admin and have them number their network with it, and then re-assign the prefix to someone else, what's the probability that you have a collision?
>> I think you need to accept that once put into use, a ULA will be in use by that administration permanently. You obviously see otherwise.  Fill me in?
> You're right, it doesn't make any sense to reassign a block once it's been assigned.  However, the question of whether to maintain, remove, or mark stale contacts in whois, and/or whether to maintain or remove rDNS from companies who've disappeared, is not so straightforward, IMO.
> Do you have any opinions on what to do there?
> Thanks,
> Scott


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