From performance issues at hosting provider Liquid Web to outages at eBay and LastPass, large networks and websites suffered a series of disruptions and outages on Tuesday. Some Internet engineers are blaming the disruptions on a novel technical issue that impacts older Internet routers.
At the heart of the issue, the growth of routable networks on the Internet overwhelmed the amount of memory set aside in infrastructure hardware, typically routers and switches, that determines the appropriate way to route data through the Internet. For the first time, the lists of routable networks—also called border gateway protocol (BGP) tables—surpassed a significant power of two (two to the 19th power or 512K). Many older routers limit their use of a specialized, and expensive, type of memory known as ternary content-addressable memory (TCAM) to 512K by default.
When the tables outgrew the space allotted for them, the routers shut down or slowed.