Posted on 2008-02-10 20:00:00
Tags: Networking, DNS, dnstracer
The first, alphabetically sorted, DNS root servers has been assigned an IPv6 address. It is not the first one, relatively speaking: f.root-servers.net, h.root-servers.net, j.root-servers.net, k.root-servers.net and m.root-servers.net had one before a.root-servers.net. So what?
Since it's the first letter in the alphabet, programs will use the a.root-servers.net as their first source to get information from the DNS system. So does dnstracer, one of my tools to gather information about possible issues with the DNS system.
To start dnstracer, you can give it an initial DNS server where it should start its queries with regarding to a certain domain. To prevent you from having to enter a.root-servers.net, you can just give the string ., which will be replaced internally with a.root-servers.net. That part works fine.
Dnstracer also has an option to disable IPv6 queries during the diagnostics phase. That part also works fine.
What didn't work fine was the part which did do the initial DNS server, the a.root-servers.net and the option to disable IPv6 queries: It didn't disable the IPv6 query for the initial DNS server. The result? The initial request for a.root-servers.net always returned the IPv6 address, even if you disabled the IPv6 queries. And since 95+% of the popuplation of this planet still doesn't have access to an IPv6 network, the tool didn't work anymore.
Well, it worked if you used b.root-servers.net instead of ., but it needed to fixed properly too.
The fixed version can be found at http://www.mavetju.org/download/dnstracer-1.9.tar.gz, the FreeBSD port is updated.
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