The Autonomica/Netnod DNS Probe System

The Domain Name System (DNS) is a hierarchical naming system for computers, services, or any resource of the Internet. It is the system that maps host names (eg www.avonsys.com) to Internet addresses. All mappings start by querying the root and walking through the domain names system to the servers that know everything about the host name.




The DNS service from i.root-servers.net (I-root), one of Internet's 13 root name systems, is provided as a pro bono service by Autonomica/Netnod in Stockholm, Sweden. To maximise the reachability and redundancy of I-root, a networking method called "anycast" is used. I-root server systems are installed in more than 35 cities across the globe, and all these installations use the same IP address and make the service available to local communities. The anycast model makes it impossible to monitor the service properly from any one single point on the network, since, from any give point in the network, only the closest installation of the service can be reached.




By deploying small "measurement computers", or "DNS probes" in great numbers all across the Internet, Autonomica/Netnod is able to watch the I-root service using "remote eyes", helping them to ensure the quality of the DNS service provided. The DNS probes report DNS reachability statistics from their "point of view" back to a collector in Stockholm, which presents a "global picture" of the DNS service to the operators at Autonomica/Netnod, who in turn will be able to notice and address local and regional problems with the service.

The DNS probes require a host that is willing to host the equipment and provide local network connectivity. Avonsys is hosting one of these probes in Suva, Fiji thereby helping in the provisioning of a healthy and efficient public DNS root service.

---