I'm in search of some information about Cogent, it's past, present and future. I've heard bits and pieces about Cogent's past over the years but by no means have I actively been keeping up. I'm aware of some (regular?) depeering issues. The NANOG archives have given me some additional insight into that (recurring?) problem. The reasoning behind the depeering events is a bit fuzzy though. I would be interested in people's opinion on whether or not they should be consider for upstream service based on this particular issue. Are there any reasonable mitigation measures available to Cogent downstreams if (when?) Cogent were to be depeered again? My understanding is that at least on previous depeering occasion, the depeering partner simply null-routed all prefixes being received via Cogent, creating a blackhole essentially. I also recall reading that this meant that prefixes being advertised and received by the depeering partner from other peers would still end up in the blackhole. The only solution I would see to this problem would be to shut down the BGP session with Cogent and rely on a 2nd upstream. Are there any other possible steps for mitigation in a depeering event? I also know that their bandwidth is extremely cheap. This of course creates an issue for technical folks when trying to justify other upstream options that cost significantly more but also don't have a damaging history of getting depeered. Does Cogent still have an issue with depeering? Are there any reasonable mitigation measures or should a downstream customer do any thing in particular to ready themselves for a depeering event? Does their low cost outweigh the risks? What are the specific risks? Thanks Justin