[arin-ppml] ARIN-prop-153 Correct erroneous syntax in NRPM 8.3

Owen DeLong owen at delong.com
Thu Jun 2 15:22:03 EDT 2011

On Jun 2, 2011, at 7:08 AM, Brett Frankenberger wrote:

> On Thu, Jun 02, 2011 at 12:14:29AM -0700, Owen DeLong wrote:
>> Quite frankly, if you sell a /19, you really don't have to announce
>> the /17, /18, and /19. You could just continue to announce the /16
>> knowing that the recipient's /19 would override your /16
>> announcement.
> Would, say, your employer go along with that?  If I have a /16 and sell
> a /19 from it, I'll end up with a /17, /18, and /19 in ARIN's records. 
> If I then seek service from HE, and tell them I want to announce the
> /16, will they allow it even though there's no record of that /16
> being allocated to me?  

Well, there should be a record. If nothing else, you should be able
to produce some record of the sale.

Additionally, there is a policy proposal which would require ARIN to
maintain such a record in public view.

> What would the standard be?  A customer can announce it if they provide
> documentation that they once held the /16 and still hold part of it? 

I can't say what my employer would do, but, in general, I would think
that in a situation where you are the holder of record of most of the
components of a larger aggregate and it is known that the smaller
subcomponents would have overriding routes (thus your aggregate
cannot cause harm) that it is reasonable to simply advertise the
aggregate rather than the subcomponents.

> Or would you allow anyone to announce a /16 if any part of it were
> assigned to them in whois?  If two or more portions of it were assigned
> to them in whois?  If more than half of it were assigned to them? 
> (Obviosuly, each provider gets to make their own decision here.  I'm
> just wondering what you'd suggest their policies should be.)

Personally, I would look at each case for what would be the smallest
total number of prefixes advertised without causing the probability
of harm.

> Certainly I agree that what you propose would work, but it would seem
> cumbersome to implement in practice, especially for any orgnaization
> seeking service from a new upstream after the sale had occurred.

It doesn't seem so cumbersome to me, but, I guess it depends on how
the upstream providers respond.

> And, of course, it all falls apart under RPKI.

I suspect that IPv4 will all fall apart long before RPKI becomes a
reality that affects the routing table.

>> There is little or no benefit to you announcing the /17, /18, and /19
>> instead of the /16.
> As long as the other /19 is continuously announced.  One downside of
> announcing the /16 is you get traffic for the /19 you sold whenever
> that /19 isn't being announced by its new holder.

If the other /19 is not announced, then, the only downside is that you
sink the traffic for it which you don't want when it isn't. It's still not
harming the party you transferred the /19 to, so, I kind of view that
as a risk you take when you transfer a small fraction of your
address space.


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