Anycast DNS DDoS attacks

How does Anycast DNS prevent DDoS attacks?

DDoS attacks keep spreading fear on the Internet. Attackers won’t stop targeting victims, therefore strengthening our security shield is a must. Anti-DDoS technology costs, but it’s worth the investment. Your online business can prevent or mitigate the threatening DDoS, and simultaneously its performance will be boosted! That’s the case with Anycast DNS. 

What’s Anycast DNS?

Anycast DNS is a mechanism for routing the traffic. It’s used for quick content delivery via individual IP addresses on all the different name servers included on a DNS network.

If you want to learn more about this mechanism you can check the following article – History of Anycast DNS.

This means any of those servers can answer DNS queries. But the big advantage is that the closest server to the location where the query was originated is the one that will answer. As a result, latency won’t be an issue. The DNS answer will be speeded up, the uptime for the DNS resolving process will be enhanced, and DNS floods commonly caused by DDoS attacks will be under control.

Unicast DNS vs Anycast DNS 

Using Unicast routing for DNS resolving process, you will have only one DNS server with a single. IP address, so each DNS query has to go to that specific DNS server. That translates to slower DNS resolution because of the long travel the DNS queries need to perform. Also, if that name server is not available, your domain can’t be resolved until it gets back on. 

Find more information about the differences between Anycast DNS and Unicast DNS.

Anycast DNS makes the process quicker. In this case, the DNS query will be sent to a network of DNS servers instead of a specific one. There, it will be routed to the closest available server.

How does Anycast DNS prevent DDoS attacks?

There are different types of DDoS attacks. They use and even combine different techniques to be more lethal. But talking in general terms, DDoS attacks’ objective is to take down their victims (servers, networks…) by sending them massive loads of traffic from multiple sources worldwide. Such sources get infected with malicious software to become the means to generate the necessary traffic to flood victims.

Having Anycast DNS, traffic can be distributed all across the network, thanks to the different servers that integrate it. Every query for an IP address has the chance to be answered not by a single server but by any other on the network. In case of a DDoS attack, the flood (big amount of queries) created for drowning the target can be distributed among the DNS servers. 

Besides this, even in the worst scenario, that the DDoS managed to drown a server, another will answer the query. In an Anycast DNS configuration, all the servers have the same IP address. So the query of a DNS client will search until one of the servers answer, skipping only the one that went down. 


Anycast DNS has proven to be an efficient strategy to prevent DDoS threats. At the time it protects, it also provides redundancy, increases the availability of the server, network, or website, and speeds it up. If you want these benefits for your online business, don’t hesitate! Get Anycast DNS for your servers, and feel a big difference!

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