The Internet Corporation for Assigned Names and Numbers (ICANN) recently put out a press release which announced that six of the 13 root servers in the root zone (presumably located in-between the Phantom Zone and the Forbidden Zone) now had IPv6 addresses.

It's a small step but one which is necessary for bigger steps to follow. With the root name servers having IPv6 addresses, it paves the way for a full IPv6 end-to-end transmission path for data. The fact that the nameservers still relied on IPv4 made at least some form of IPv4 over IPv6 necessary for Internet transmission.

We were able to ask a few questions about the IPv6 assignment to ICANN and got answers from David Conrad, Vice President of Research and IANA Strategy.

NPD: Why only six of the 13 root servers?

Conrad: 6 of the 13 were ready at this time. Each of the root servers is run independently and are funded through internal means (that is, in general, no one is paying any of the root server operators to operate a root server directly). The 6 that requested ICANN add IPv6 records were the ones that had finished setting up their IPv6 infrastructure sufficiently to provide service.

NPD: Could you explain a bit about the 512 byte limit on the packet sizes?

Conrad: The original specification of the DNS protocol chose 512 bytes as a reasonable approximation of the largest packet that could get through the Internet (of the time, circa 1983) without being fragmented. Enhancements to the DNS protocol since then have allowed for an increase in that limit (specifically, requesters can indicate how large a packet they're willing to accept).

NPD: How will computers get the new info about the root name servers' new IP addresses?

Conrad: The only computers that will actually need the new information are DNS caching servers. When a caching server starts up, it asks one of the 13 root servers it has pre-configured (the root hints) for an up-to-date list of all the root servers. It then uses that new list.

DNS caching servers are typically operated by ISPs or the IT departments of large enterprises. Average PCs and workstations send their DNS queries to these caching servers.

NPD: Would this require operating system upgrades/patches?

Conrad: A patch will likely be supplied to make the change in the root hints permanent (the updated list obtained by the caching servers isn't generally written to disk), but as described previously, caching servers will be able to use the new addresses without the patch.

Is this a significant move towards standardizing Internet traffic on IPv6? Tell us your thoughts in our comments section below.