Anycast DNS implementation

Since the spring of 2013, we have begun to implement Anycast technology for our NS-servers. Below we briefly describe what this technology is and what advantages it gives to our customers.

Original in the selectk corporate blog

What is Anycast?

Server response time depends largely on its geographical distance from the point of request. As a rule, the smaller the distance between the server and the point of request, the shorter the response time. But the speed of data exchange between the server and the user's computer also depends on a number of factors: the hosting equipment, the characteristics of the Internet channel it uses, etc. Packet exchange between sites is not always carried out by the shortest and most convenient route.
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One of the effective ways to optimize the movement of packets is the use of technology Anycast. The word anycast can be translated as "sending to anyone" or "arbitrary sending." Anycast is a packet sending method in which data is sent to the closest of potential recipients.

How it works?

To use Anycast technology on the client side, no special servers, networks or special clients are required.

The meaning of the Anycast method is to announce the same IP address prefix from several network points simultaneously via BGP. As a result, the data is transmitted along the shortest route - to the nearest host, to which an announced IP address is assigned. In this case, the concept of “short route” in this case is interpreted not in a geographical, but in a topological sense.

Anycast Benefits

So, on the basis of Anycast technology, you can create a distributed DNS system with a single address space, which allows you to solve a number of problems.

Firstly, Anycast can significantly increase the level of reliability and resiliency of the DNS service. If one of the nodes of the system for one reason or another fails, it does not affect the operation of the system as a whole: the entire load will be redistributed to other servers.

Secondly, due to the use of Anycast, the interaction time is reduced by reducing the network distance between the client and the server.

Thirdly, using Anycast you can solve some security problems. The system built on the basis of Anycast is resistant to ddos ​​attacks: they can be neutralized by localizing on single nodes and limiting the area of ​​impact. Resilience of the system with an increase in the number of requests can be increased by simply scaling with the distribution of the load. When one of the nodes is compromised, it may well be turned off, and its load will be distributed over the remaining elements of the system.

Points of presence

Our NS servers are located in three cities of Russia (St. Petersburg, Moscow, Yekaterinburg), as well as in Europe and America. Points of presence are marked on the map below.

Conclusion

The use of Anycast technology increases the level of reliability, resiliency and security of the DNS system. We have already begun to implement a number of innovations based on this technology.

So, in the near future, our customers will be available services in various types of balancing based on DNS. In the domain control panel, it will be possible to specify IP addresses to which requests will be sent depending on geographic location. This will give our customers the opportunity to more flexibly distribute requests from their users.

Other innovations are planned, which we will discuss in the following publications.