Anycast

Problem

Users worldwide should access: 8.8.8.8 But sending everybody to one physical server location would create latency and availability problems. How can the same IP address exist in many locations?

Solution — Anycast

Multiple locations advertise the same IP prefix through routing.

         8.8.8.8
       ↙    ↓    ↘
Europe     US     Asia

Internet routing directs users toward an available routing path to that address.

Core idea: anycast lets multiple locations advertise the same IP address/prefix.