Anycast DNS: History & Advantages

If you still don’t use Anycast DNS, pretty sure you have heard network administrators talking about it. If it’s about getting better performance, uptime, or faster DNS resolution for your domain, Anycast DNS is popular and good advice.

What is Anycast DNS?

Anycast is a network method for addressing and routing. DNS adopted it, so Anycast DNS is the possibility of having a single IP address and multiple name servers in different locations that can provide it when requested.

The objective of having name servers in different locations is to be closer to users worldwide. Let’s think a user requests a domain so he or she will get an answer from the nearest name server that has the same IP address. A shorter distance will require a shorter route. This will result in higher speed for the DNS domain resolution and a considerable latency reduction.

History of Anycast.

Anycast has existed since 1989, but it was until 1993 that the Internet Engineering Task Force (IETF) properly documented this routing method in the RFC 1546, “Host Anycasting Service”. That document described how this method improves the performance of a network and provides what they called “autoconfiguration of DNS resolvers”.

Back then, only some servers supported Anycast addresses. Others directly discarded data packets heading to Anycast addresses. Another issue was that some servers managed to intercept communications and deviate traffic to themselves by forging their IP address. But technology evolved and DNSSEC got born and solved these security problems.

By 1999, Anycast had already started working with IPv6. And during the 2000s, root DNS servers used Anycast DNS to enhance redundancy.

Before, when the Internet and its traffic were smaller, Unicast worked ok. This routing method was a one-to-one way, meaning data were sent from a source (node) to only a destination.

Advantages of Anycast DNS.

Quicker DNS response.

With more and worldwide distributed DNS nameservers, answers to DNS queries are faster. The closest server will give these answers to the location where the DNS queries originated.

Effective redundancy.

Having only one nameserver can be risky and cause downtime if this server fails. But Anycast DNS means a network with multiple nameservers. Since all of them can lead users to the same IP address, if a server fails, there will be more Anycast DNS servers that can give a proper answer.

Load balancing.

With more than a single server, the possibility of distributing the traffic is real. There’s no need to stress one or another server. This is not a minor advantage! Just think about DDoS attacks. To prevent big loads of traffic, either malicious or legit (like sudden spikes due to high season, special sales, etc.), can make your servers struggle is a great advantage.

Scalability when you need it.

Quality providers of Anycast DNS allow you to add or remove servers easily.

Conclusion.

Anycast DNS offers big advantages for your online business. Fast speed, reliable service, and constant uptime for your clients. It’s worth a try, isn’t it?

Published by Adrian

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