The DNS root servers, the backbone for handling all domain name queries on the Internet, used to all be located in North America. Not anymore. Thanks to the anycast technology used by six of the root server adresses, the actual locations of the servers have been spread all over the world and their numbers increased from 13 to 123, giving the Internet a much more reliable DNS backbone. Root servers are spread over 81 cities in 46 countries.
North America leads while Africa and South America fall behind
The spread of the root servers isn’t entirely even. North America has 40 root server locations (32.5%), Europe has 35 (28.5%), while on the other end of the spectrum you find South America with six (4.9%) and Africa with only 3 (2.4%). It should also be pointed out that two of the locations in Africa are in Johannesburg, South Africa.
It should be mentioned that this is still a much better spread than the “original” situation before anycast when USA basically held all of the root servers.
As it looks now, the general spread of the root servers is closely matched to Internet infrastructure and usage, which of course makes perfect sense.
The top countries
These are all the 46 countries sorted by how many root server locations they have.
36 root servers: USA 5 root servers: Japan 4 root servers: Australia Canada China Italy Netherlands United Kingdom 3 root servers: Brazil Germany India Singapore South Korea 2 root servers: Finland France Indonesia New Zealand Russia South Africa Spain Sweden Switzerland United Arab Emirates 1 root server: Argentina Bangladesh Belgium Chile Czech Republic Greece Hungary Iceland Ireland Israel Kenya Malaysia Mexico Norway Pakistan Poland Portugal Qatar Romania Taiwan Thailand Turkey Venezuela
The top 10 cities
The top 10 cities account for 34 of these 123 root servers. In other words, 8.1% of the cities count for 27.6% of the servers.
4 root servers: Amsterdam London Los Angeles Tokyo 3 root servers: Chicago Miami New York City San Fransisco Seoul Singapore
All the remaining cities have either 2 or less root servers.
Final thoughts
DNS root servers are vital to the Internet, and for the best performance and reliability world wide, the geographical spread of the root server network is very important. The less sensitive it becomes to local disturbances (e.g. natural disasters, wars, simple network outages), the better.
Some of the data above indicate that currently the spread isn’t always as even as one would wish. However, it is very likely that as the Internet keeps growing, many more root servers will be added, hopefully spreading the network even more and not concentrating it to a limited amount of locations.
