DNS is a critical element of Internet networking infrastructure. Ensuring the reliability of DNS is important, since without reliable DNS, a user is less likely to actually reach their intended destination on the Internet.
A new study commissioned by VeriSign, provides some interesting findings on the state of DNS availability. VeriSign is a company well-placed to understand DNS, since they operate the .com and .net registries as well as helping to maintain some of the root zone DNS servers for the Internet.
The DNS availability study looked at the availability of the Alexa 1,000 websites during the second quarter of 2011. For those sites that manage their own DNS, the minimum availability was recorded as 95.30 percent. For those that host with a third party managed DNS vendor, minimum availability was reported at 97.14 percent. According to VeriSign that 2.3 percent minimum difference translates into approximately 40 minutes of daily downtime.
Sean Leach, VP of Technology at VeriSign told InternetNews.com that companies are not spending enough time to properly address the challenges of DNS management. While those that manage DNS themselves were shown to have a minimum availability less than the average for managed vendors, Leach also sees flaws with some of the managed vendors.
The VeriSign study does not specifically identify which third party managed DNS vendors were included in survey. That said, Leach noted that it does include VeriSign, which offers its own managed DNS service. Leach stressed that that the VeriSign service operates at 100 percent availability. He noted that VeriSign did not want to call out those other DNS vendors that didn't hit 100 percent.
While there was a gap on the minimum availability of DNS servers, the gap become significantly smaller when looked at from a different perspective. The overall global average availability for internally managed DNS was 99.67 percent. The overall global hosted DNS average availability was reported by VeriSign to be 99.78 percent.
"The reason why we went with minimum availability is because it shows the downtime better," Leach said. "Average availability spread across an entire month evens out."
"So even though the sites are up and running most of the month there are certain times during the month where the sites are down," Leach added.