On Wed, 05 Mar 2014 15:23:55 -0500, William Herrin said:
Hi folks,
Can anyone tell me about a situation in which a route which was not valley free was not a result of a misconfiguration or a bad actor? For those who don't recall the terminology, a network path is valley free if it crosses exactly zero or one free peering links when traveling between the two endpoints.
Assume 3 providers A B and C, where you have a single-homed customer on A and a single-homed customer on C, and A and C don't peer. Traffic may end up going thorugh an A-B peering and a B-C peering. And whether A-B and B-C are a free peering or a paid transit is a business deal, outside the scope of BGP, unless you want to abuse communities... Are A and/or C "bad actors" for not peering? Jury is still out on that one.