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Re: classful routes redux

  • From: Russ White
  • Date: Fri Nov 04 09:08:28 2005

Hash: SHA1

>>>A routing table capable of handling a flat 2^128 addressing space goes
>>>beyond the realm of known physics -- and flat 2^64 comes close, at least for
>>>a while (consider semiconductor atomic weights, and the fact that 1 mole is
>>>approximately 2^79 atoms).  That's quite a stretch, but should give a hint
>>>as to why flat addressing does not work for every model.
>>Come on now, a lot of new routing gear made today can just barely handle 
>>2^18 routes, and even the high end stuff tops out at 2^20. We're nowhere 
>>near handling 2^32 routes even for IPv4, nor should we be, so lets not 
>>start the whole "but ipv6 has more space therefore routes will increase to 
>>7873289439872361837492837493874982347932847329874293874" nonsense again.

>>Removing the extreme restrictions on IP space allocation by being able to 
>>allocate chunks so large that you would RARELY need to go back for a 
>>second block would immediate reduce the size of the routing table. Let me 
>>state the stats again for the record:
>>Total ASes present in the Internet Routing Table:                 20761
>>Origin-only ASes present in the Internet Routing Table:           18044
>>Origin ASes announcing only one prefix:                            8555
>>Transit ASes present in the Internet Routing Table:                2717
>>There are just not that many distinct BGP speaking networks out there, nor
>>will there ever be. NOW is the time to make certain that IPv6 deployments
>>makes sense in practice and not just in theory, so we don't work ourselves
>>into exactly the same mess that we did in IPv4. Lets stop trying to solve
>>theoretical scaling problems which will never happen at the expense of
>>creating problems which actually DO exist, and apply a little bit of common

> whilst i'm at the mic here, ditch the idea of microassignments, just give out a 
> standard /32 block ... lets not start out with ge 33 prefixes in the table when 
> theres no need

Hmmm.... Some interesting points:

- -- 2^32 is still larger than 2^20, which is claimed to be the largest 
feasible size, above.

- -- BGP is currently moving to a 2^32 space for AS numbers. That's odd, 
if there's only 18,044 origins in the current table, and it won't ever 
grow to much more--how'd we lose 40,000 or so AS numbers, that we now 
need more than 64,000?

Just curious.



- -- 
[email protected] CCIE <>< Grace Alone

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