On Mar 23, 2009, at 1:50 PM, Ted Hardie wrote:
At 12:06 PM -0700 3/23/09, Fred Baker wrote:
At the end of the day, I think that there is a place for PI - with a
handwaving gesture, it ca be argued that anyone that can justify an
AS
number and in fact has multiple upstreams is probably well-served by
PI. That said, the line of reasoning that takes the RIRs into PI
space
ultimately results in the same kind of swamp we have in the IPv4
route
table. If "insanity" is defined as "applying the same algorithms to
the same data and expecting a different result", those who complain
about the IPv4 route table and request PI space are insane.
And those who recommend the general use of an address range which
is deliberately designed to have very limited aggregation are
not? ULAs don't do CIDR, last I heard.
They do it just as well as any other /48, which is what the RIRs are
allocating as PI space.
There is a very serious risk
in deploying ULAs that the cost of getting a routing table slot for
one is a function of how hungry a set of ISPs gets. There seems to
me a legitimate worry that deploying on the basis of ULA+PA
because of concerns with routing table growth could backfire badly.
If you find it doesn't work for any compelling application, the result
seems to be market pressure to route ULA. And the routing table goes
boom in yet another tragedy of the commons.
So you would prefer to allocate PI space in /48s and guarantee the
routing table explosion.
Perhaps I'm paranoid, or fret too easily. But I wouldn't bet on
insane.
Well, you and I can discuss that in the presence of suitable adult
beverages. :-)
I think that if the local "cost" to generate a ULA is anything above
0 (and I include maintenance calls), the chance of deployment based
on link-local gets to be pretty high. If that doesn't worry you,
given
3484, I'd like to understand why. All v6 scopes have collapsed at
that
point, right?
<head scratching>
<delay/>
</head scratching>
So I work for one of those evil vendor companies that makes these
things. I find myself thinking in terms of "how difficult is it to
make a ULA that is likely to be different than someone else's ULA". I
find myself wondering not whether, but how many, random number
generators are implemented in such devices, and whether a seed like
the time of day at boot or the MAC address of the interior interface
might come into play as a seed. Or what happens if I just use the
lower N bits of the MAC address stuffed into the ULA top prefix.
And I think about the issues that using a link-local address in a non-
NAT'd environment brings into play.
I think the ULA would be orders of magnitude simpler than trying to
use link-local in a non-local scope. really.
How does this relate to the NAT66 proposal?
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