How BGP can break the Internet

from CloudFlare

In 2004 a Turkish Internet service provider (ISP) called TTNet accidentally advertised bad BGP routes to its neighbors. These routes claimed that TTNet itself was the best destination for all traffic on the Internet. As these routes spread further and further to more autonomous systems, a massive disruption occurred, creating a 1-day crisis where many people across the world were not able to access some or all of the Internet.

Similarly, in 2008 a Pakistani ISP attempted to use a BGP route to block Pakistani users from visiting YouTube. The ISP then accidentally advertised these routes with its neighboring AS’s and the route quickly spread across the Internet’s BGP network. This route sent users trying to access YouTube to a dead end, which resulted in YouTube being inaccessible for several hours.

These are examples of a practice called BGP hijacking, and it isn’t always accidental. In April of 2018, attackers deliberately created bad BGP routes to redirect traffic that was meant for Amazon’s DNS service. The attackers were able to steal over $100,000 worth of cryptocurrency by redirecting this traffic to themselves.