Another v6 question

Max Pierson nmaxpierson at
Tue Jan 25 12:19:34 CST 2011

Hi List,

Sorry to bring up yet ANOTHER v6 question/topic, but this seems to be one
that I cannot get a solid answer on (and probably won't and in the event
that I do, it will probably change down the road anyways), but here goes.

>From the provider perspective, what is the prefix-length that most are
accepting to be injected into your tables??  2 or so years ago, I read where
someone stated that they were told by ATT that they weren't planning on
accepting anything smaller than a /32. So what if I get my shiny new /48
from ARIN and am already multi-homed??? Does ATT not want my business (which
they wouldn't get if the first place, but for argument sake, yes, I chose to
pick on ATT, sorry if I offended anyone :)  I already see /40's /48's ,etc
in the v6 table, so some folks are allowing /48 and smaller, so what is the
new /24 in v6?

I only ask due to the fact that ARIN's policy for end-users is /48 minimum
(which is what i've been telling folks to apply for or applying for it on
behalf of them).

Second, as I was crunching a few numbers to get a rough estimate of what a
global table would look like in say 3 or 5 years after v4 is exhausted (I
understand that it's completely unpredictable to do this, but curiosity
killed the cat I guess), and in a few cases, I stopped due to the shear size
of the amount of prefixes I was coming with. Where i'm getting with this is
has anyone done any crunching on prefix count for v6 (as in estimates of
global table usage with the various prefix lengths seen above _based_ on the
initial allocation of the v6 space (not the entire v6 space itself)). I'm
interested to see how long before we have 96Gb's of TCAM/Memory (take you
vendor of choice) in our routers just to take a full table. (Not to mention
still having all of the ipv4 de-agg crazyness going on today. Seriously, who
lets /28 and /32's in their tables today? And this will only get worse as v4
fades away).

Would love to hear comments from anyone that was rejected peering due to
only having a /48. Would also like to hear from anyone about projected table
sizes if anyone has done any research on this.

Heading back to my cave now to hopefully hear some good responses. (An
someone please correct me if any of the above is incorrect).


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