How Verizon and a BGP Optimizer Knocked Large Parts of the Internet Offline Today

On June 24, 2019, a massive route leak impacted major parts of the Internet, including Cloudflare. This occurred when a small company in Northern Pennsylvania became a preferred path for many internet routes through Verizon, a major internet transit provider. The problem was exacerbated by the involvement of a "BGP Optimizer" product from Noction, which split up received IP prefixes into smaller parts. This caused many websites on Cloudflare and other providers to be unavailable from large parts of the Internet. The incident was resolved when DQE Communications worked with Cloudflare to stop advertising these optimized routes to Allegheny Technologies Inc. Despite this being outside their control, Cloudflare apologized for the disruption and encouraged network operators to adopt better routing security through systems like RPKI.