What started as with a few messages on several ISP focused mailing-lists has been confirmed by Cogent in a press release today: Sprint-Nextel and Cogent have interrupted their peering connections, and as such customers from both networks can no longer reach the other network.

As a lot of you know, this is not the first time Cogent has been in the middle of a peering dispute, and so far, with no information from Sprint-Nextel on the matter, it is unclear what the reason behind the issue is, and who actually started the trouble.

Update: Head over to the Renesys blog to get Todd Underwoods detailed analysis of the situation. As always, worth reading. Their data gives details about the number of networks which are affected by this dispute:
- 289 autonomous systems are single homed behind Cogent
- 214 autonomous systems are single homed behind Sprint
All of these networks are currently not able to reach each other!

Randy Epstein (President, WV Fiber) informed the readers of the NANOG mailing list that the WV Fiber network (AS19151) is currently also affected by this since they only contract with Sprint for Transit, and is settlement free with the rest of its peers, which doesn’t include Cogent anymore since late last year when Cogent depeered AS19151 for unknown reason.

Update 2: Further information can be found in an article at the Arbor Networks blog, giving also an idea of the amount of traffic exchanged between AS174 and AS1239. But still, no information has surfaced so far about the actual cause of the de-peering.