What is Anycast DNS?

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Typically, computers and devices connected to the internet are uniquely assigned an IP address, this is called Unicast.

Anycast on the other hand, allows the same IP address to be assigned to multiple servers, not necessarily located together. When a request is sent to an IP it is routed to the closest server. If one of the servers is down the request is seamlessly routed to the next computer. This can have many advantages!

A Fast Food Analogy

Think of Anycast DNS as a global chain of fast-food restaurants, all using the same brand name and menu. When you're hungry, you go to the nearest outlet rather than traveling to one specific location every time. In contrast, Unicast DNS is like having just one restaurant location that everyone must go to, no matter where they are.

Contrasting Anycast and Unicast DNS

Anycast DNS: Multiple servers share one IP address. Your device connects to the nearest one, like going to the closest fast-food outlet.

Unicast DNS: Each server has its own unique IP address. No matter your location, your device always connects to this specific server, as if there were only one restaurant you could visit.

Benefits of Anycast DNS

1. Quick Responses: Just like how going to the closest restaurant is quicker, Anycast DNS reduces website load times by connecting you to the nearest server.
2. High Availability: If one server goes down, your device switches to another, similar to how you'd choose another nearby restaurant if one were closed.
3. Traffic Distribution: With many servers to handle queries, the load is evenly distributed, preventing any one server from being overwhelmed.
4. Security: In case of cyber-attacks, harmful traffic is divided among multiple servers, making the network more resilient.

Anycast lends itself to services like CDNs and DDOS protection.