Now I'm wondering if that is even a valid assumption. Maybe the truth is more like this:
[backbone provider A] [backbone provider B] / \ / \ [intermediate A] [intermediate C] [intermediate B] / \ [ISP A] [ISP B]
and if the problems is with intermediate C, I'm probably SOL. Clearly, I would want my ISP to insist that his upstream providers not allow such unreliable topologies to be used.
Ken Wallewein CDP,CNE,MCSE,CCA,CCNA
This is a close approximation of the actual topography - though there may be a few more 'C's between A and B. The reality is that there are a couple of really large providers and the majority of networks connect either directly or are no more than a couple of hops off of the largest networks. See http://www.caida.org/analysis/topology/as_core_network/AS_Network.xml. End users trying to fix routing loops usually have fairly limited success due to the difficulty in notifying the affected providers - this is an issue that has been hashed to death and I don't think anyone is in the mood to discuss it again. Your 2 upstream providers are the ones you need to hold responsible - it's their job to get your packets where they need to go. It is entirely possible that various networks on the Internet will not be able to talk to other networks due to policy and peering decisions made by the various providers. Providers that do not provide access to the majority of the Internet usually find they loose market share quickly - this tends to be self correcting in fairly short order. Mark Radabaugh Amplex (419) 720-3635