I began noticing something was fishy a couple of days ago. While at work I was trying to visit certain sites, such as RealNetworks, they were not reachable. Oddly enough, the same sites that were unreachable at work were perfectly fine from home. Turns out Level 3 and Cogent have had a falling out.
On Wednesday, network company Level 3 Communications cut off its direct “peering” connections to another big network company called Cogent Communications. That technical action means that some customers on each company's network now will find it impossible, or slower, to get to Web sites on the other company's network.