Anycast, a network addressing and routing method, enables DNS routing requests to be answered by the closest available instance of the IP address queried. This means Internet requests are answered faster, connecting your customers and employees to their end destination faster. Any IT professional curious about how Internet traffic routing works can find out more in this article on anycast.
Anycast at its core
The DNS protocol is designed to find the computer friendly IP address for a location on the Internet when given a human friendly domain name. Anycast is one of 5 routing methods that the Border Gateway Protocol (BGP) can use to link the domain name to an IP address. Anycast looks for all recursive servers that broadcast the IP address for the queried domain and forwards the query to the closest location that can respond. Most of the time, this means it’s taking the shortest available path to the query’s answer. This makes anycast a good solution for fast name resolution.
What else can anycast do for me?
In addition to fast domain name resolution, anycast is a more resilient routing method than unicast (one query to one location), because anycast has the option of getting its answer from more than one location. NS1 has 25 points of presence, or POPs, worldwide. By using an anycasted network, NS1’s filter chain technology can manage the flow of queries to the DNS resolvers. This enables NS1’s network to isolate outages due to a known global issue such as a cut fiber or clogged Internet segment.
Does anycast work for IPv6 as well as IPv4 addressing format?
Anycast works for both IPv4 and IPv6. Due to the slow adoption of IPv6, there are about 10x more routes for IPv4 than IPv6. What this means for NS1’s service is that there are many more paths for traffic to reach DNS resolvers using IPv4 than there are on IPv6. Sometimes this limited use of IPv6 means having fewer paths for DNS resolution and can mean additional latency when executing a DNS query. Having an anycast network at your service limits that latency.
Do I need to do anything special to use anycast with NS1?
NS1’s anycast network and POPs are automatically available to your domain as soon as you delegate your first zone to NS1. Contact us to see what our domain name resolution technology can do for you.