Think of it as the internet's latest growing pain. It's a problem that networking geeks have seen coming for awhile now, but yesterday it finally struck. And it's likely to cause more problems in the next few weeks. The bug doesn't seem to have affected core internet providers?companies like AT&T and Verizon, which haul vast quantities of data over the internet's backbone, "but certainly there are a number of people that were caught by this," says Craig Labovitz, founder of network analysis company Deepfield Networks.

The issue affects older, but widely used, routers such as the Cisco 7,600. These machines store routing tables in their memory?directions describing the best way for packets of data to move to their ultimate destination?but some routers max out when their list of routes hits 512,000. Different routers have different total routes in memory, but most of them have been closing in on the 500,000 level for a few months now. Yesterday Verizon published an extra 15,000, kicking many routers over the 512,000 crash-point.