The problem with the current Domain Name System and TTL (Time to Live) became glaringly apparent recently when the entire country of Sweden utterly disappeared off the Internet grid. A tiny typo found in a server script was the culprit and, while seemingly insignificant, it had a dramatic impact on all “.se” web sites felt for weeks.
With the current TTL system, a caching or recursive nameserver sends queries to authoritative nameservers requesting a resource record. The recursive nameserver then caches the record for the specified TTL. The standard TTL within a DNS record is usually set at 86,400 seconds or 24 hours. In some cases, the TTL is set for a longer amount of time and can be as long as a week. Even though the error had been caught and corrected in less than an hour, a number of “.se” domains remained inaccessible for at least a week.
These types of issues clearly indicate a need for real-time update processing. Neustar and OpenDNS have combined resources to answer the call with the DNS Real-time Directory. This new service is comprised of three elements: a combined collection of DNS changes, authoritative nameservers, and recursive nameservers. The DNS Real-time Directory bypasses the TTL cache settings and allows for nearly immediate updating of IP and DNS records.
OpenDNS has been using the new service offered by Neustar for over a month and recently publicly announced the service. The announcement just happened to coincided with the latest Google DNS service release. OpenDNS founder David Ulevitch posted out his thoughts on the two services. An online dashboard to control web site accessing, DNS caches that are more up-to-date than Google’s, and differing views on user privacy are the biggest differences.
Personally, I’m excited about the prospect of real-time DNS updates. Having dealt with the tiniest of typos in server updating scripts, I have had to deal with the hassle of waiting for DNS records to propagate throughout the Internet after making corrections. With each passing hour, a business domain that is not accessible ends up equaling to a loss of new and current customers. 24 hours can seem like an eternity. A week? Pure hell and a public relations nightmare for many businesses.
Patience is tossed out the window, it seems, when it comes to all things Internet – whether a web surfer or an online business. Solutions to long TTL records leading to domain inaccessibility are needed as can be seen by the Swedish domain name fiasco. The DNS Real-time Directory not only addresses this issue but is yet another step in the direction of a speedier Internet experience for all.
