Introduction to Anycast DNS

Anycast DNS explained.

Through Anycast DNS, several servers that are located in different geographical points can provide the same IP address. The DNS data for your domain name is duplicated on more than one server. You are able to choose a specific number of servers, depending on your needs. That way, your overall presence is going to be better.

When you are using Anycast, the most nearby server is going to answer the request of the user. In case one of your servers is offline due to maintenance or down for some reason, your website is still going to be reachable. The request will move to the second closest and available DNS server to resolve. As a result, the user’s request is going to be answered faster. Also, the overall experience is going to be improved in terms of loading time, waiting for a response, and so on.

Discover more details about Anycast DNS

How does it work?

Anycast network routing can route incoming requests over various data centers. The requests arrive in a singular IP address associated with the Anycast network. So, the network spreads the data based on a priority method. Choosing a particular data center will typically be adjusted based on reducing latency and selecting the data center closer to the requester. 


  • Better uptime. It is possible for a server to fail, but the chance of a group of servers to fail at the same time is very low. So, your website is going to have better uptime, and your users could access it at any time.
  • Faster response time. The waiting time is way shorter when your servers’ responses are fast. Less potential clients are going to abandon your website.
  • Improved security. You can rely on other servers in case one of them gets compromised.
  • Rank on search engines. User experience includes waiting for a response, loading time, etc. Search engines don’t miss to rank better or worse your site based on these factors.

Anycast vs. Unicast DNS Routing

  • In Unicast DNS routing, the DNS resolver, an element on the DNS server accountable for discovering the authoritative DNS record for the demanded hostname, can get a list of many DNS name servers. It searches on the first one on the list. Then waits till it replies or there is a timeout, and then it is able to try the next on the list. This can cause high latency.
  • In Anycast DNS routing, resolvers are configured with only one anycast address for each group of name servers. That way, the latency is eliminated. The timeout delays with a non-responsive nameserver do not happen. Anycast routing automatically excludes unreachable points of presence (PoP). The DNS resolver is always routed to the closest and well-performing DNS server.

Why use Anycast DNS?

In case you have a website, service, or app, you probably want reliability and speed in each location. Nobody wants angry customers. With Anycast DNS, you achieve excellent performance at various places and handle the traffic effectively. The better network performance leads to more satisfied clients and then probably to more sales.

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