Sorry, I thought we were discussing all multi-homing. Your example doesn't help the business whose ISP suffers a business failure (such as DSLnetworks, Flashpoint, et al), only the case where the access provider fails SLA. To put it bluntly, a single circuit, to a single business, while annoying, doesn't cause wide-spread outages when it fails. It is thus, the lesser-order case. The case I thought was under discussion is when an ISP dumps something on the order of 10^3 or more customers when they fail. I understand that NorthPoint abandoned ~100,000 customers when they sold their backbone to AT&T and AT&T didn't pick up the subscribers. I will wager that many of them were /24s. DSLnetworks had over 700 Covad customers, FlashPoint was larger. For various definitions of "wide-spread", this is a much larger issue than a broken copper-pair. I suspect that it also has a much higher likelyhood of occurance. Especially, in the current business shakeout. Guess what ... it won't stop. This sort of problem will be with us forever. We should find a solution ... someday ... ya think? Business failures are on one side of the problem and CIDR aggregation is on the other.
-----Original Message----- From: RJ Atkinson [mailto:rja@inet.org] Sent: Tuesday, April 03, 2001 11:26 AM To: Roeland Meyer Cc: nanog@merit.edu Subject: RE: Faster 'Net growth rate raises fears about routers
At 13:55 03/04/01, Roeland Meyer wrote:
The problem with this, if done, is that we back right into the other problem of prefix filtering.
No. These are separate tail circuits to separate POPs of the same ISP. So that one ISP only needs to advertise its fully aggregated prefix. So the problem you postulate does not arise in this particular situation.
What is the other ISP to do?
You didn't read closely enough. 2 tail circuits, 2 POPs, but only 1 ISP was the scenario outlined. It works quite well, provided one picks the ISP thoughtfully.
Ran