Actually, where I have mostly seen the biggest problems with the Cogent remote BGP hacks is when their forwarding decisions in between your router and their BGP speaking router don’t actually deliver your packets to the BGP speaking router and your traffic starts veering wildly off course to god knows where.
Likely they’ve gotten better at avoiding this over the years, but there were times when it resulted in very interesting loops and very strange paths that often did not ever reach the intended destination. Worse, when you encountered one of these hairballs, finding someone at AS174 with enough clue to understand your traceroutes let alone fix anything was an additional challenge. Owen
