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Re: WG Action: Conclusion of IP Version 6 (ipv6)

  • From: David Conrad
  • Date: Tue Oct 02 18:51:27 2007


John,


On Oct 2, 2007, at 6:32 AM, John Curran wrote:

At 5:39 AM -0700 10/2/07, David Conrad wrote:
What happens if folks can somehow obtain IPv4 address blocks
but the cumulative route load from all of these non-hierarchical
blocks prevents ISP's from routing them?

Presumably, the folks with the non-hierarchical address space that might get filtered would have potentially limited connectivity (as opposed to no connectivity if they didn't have IPv4 addresses).

Sure, right along ISP boundaries. If we really foul things up, you'll see some companies buying multiple "Carrier Internet"
connections, one from each major carrier to get to firms which are only reachable via "the AT&T Internet", the "Verizon Internet", etc. Won't that be fun?

"Internet doomed, MPEG (not) at 11:00".


I'll admit getting a bit weary of the FUD. It would be a bit more interesting if we hadn't been here before.

I'm sure we can all come up with nightmare scenarios. The one you describe seems a bit on the edge of likelihood to me given the limited desirability of the limited networks you describe. It would seem to me that if AT&T and Verizon were to attempt a path as you describe, Comcast or NTT or BT or Reliance or ... would likely encourage them down that path.

Realistically, I suspect there are less than 100 /8s that fall into the category of address space whose terms of use are sufficiently ambiguous that they are likely to be traded. Rounding up, assuming those /8s are all shattered down to /24s (won't happen of course since ISPs will want to get the largest aggregates they can, but for sake of argument...), that would mean an additional O(1M) routes dumped into the routing system over the remaining lifetime of IPv4.

Older routers will indeed fall over, as they are going to fall over when we go over 240K routes, so folks will upgrade. The cost of the upgrade will be passed onto customers. ISPs not able to upgrade have the choice of (a) prefix filtering (making their service less attractive to their customers), (b) pointing default to their upstream (s), or (c) going out of business.

Everything will get incrementally more expensive but I remain somewhat skeptical that there will be a fundamental change in the way the Internet works.

Regards,
-drc