Anycast is a network addressing technique where multiple servers in different global locations all advertise the same IP address into the routing system (usually via BGP).
Your router then selects the “nearest” server based on:
- Lowest latency
- Shortest AS path
- Routing policy preference
👉 Anycast = one single IP address served by multiple servers across the world.
🧙♂️ How Anycast Actually Works (BGP Magic)
Behind the scenes, BGP makes Anycast possible.
Here’s the flow:
1️⃣ Advertise the Anycast prefix — each PoP (Point of Presence) pushes the IP via BGP/OSPF.
2️⃣ Routing picks the winner — global routers calculate path cost and forward packets to the closest location.
3️⃣ Failover happens automatically — if India PoP dies, it withdraws the BGP route → traffic shifts instantly.
Client → ISP → Internet backbone → Nearest Anycast node
- No DNS changes
- No user action
- No downtime
Unicast = every customer must go to one original branch
Anycast = customers are automatically routed to the nearest branch of the same restaurant
🔗 Want the full breakdown? Check out the complete blog post here 👉 || The Hidden Internet Superpower: How Anycast + BGP Make Websites Faster and Unstoppable ||
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