Attention IT mavens: It's time to update your DNS servers.

Last week, ICANN setup a new IP address for one of the thirteen "root name servers" that oversee DNS queries across the net, and it plans on retiring the old address as soon as the late spring.

It's a rare change to the internet's domain name system that will likely take several years to completely iron out. "These root addresses are, in some ways, the most permanent configuration option on servers across the world," Kim Davies, ICANN's manager of root zone services, told us. "Ultimately, when you renumber one of the root name servers, it needs to be reflected in almost every machine connected to the internet."

ICANN (Internet Corporation for Assigned Names and Numbers) is responsible for the root name server dubbed L.ROOT-SERVERS.NET. On November 1, as announced on the official ICANN blog, the organization officially rolled out a new IPv4 address for the server: 199.7.83.42. The old address (198.32.64.12) will be available for at least six months, but ICANN is urging DNS operators to go ahead and update any reference to the address on their own servers.

The change has been made for two reasons. For one, the old IP address wasn't officially under ICANN's control. But more importantly, the organization wanted to make the switch to "any casting," a way of streamlining DNS queries.

Each "root name server" is actually a collection of several physical servers, and with anycasting, ICANN can spread its machines across multiple geographical locations.

"Previously, our root server was just in one location: Los Angeles," Davies explained. "Anycasting allows us to route traffic to the root server more effectively by placing services in multiple countries. It advertises across the network in such a way that users across the planet will always access the root server from the nearest location."

Yes, the likes of Microsoft will rejigger the address on popular DNS software, but many servers will still a manual update. "There are a number of servers out there that either aren't automatically updated or have very old operating systems," Davies said. "Left to their own devices, they will effectively try and connect to the old address forever."

Sort of. Machines trying to connect to the old address after its taken down will automatically try again on one of other twelve root name servers. "Once those machines do connect to a working root server, they'll ask the root for an up-to-date list of IP addresses, and they'll make the change on their own."

So, if you feel like it, you can procrastinate. The net will survive. "DNS is fairly robust," is the last word from ICANN. "We'll be able to self-correct."®

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