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What's the difference between a root nameserver and a TLD (top level domain) server?

Ellie Kesselman
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Wintermute
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2 Answers2

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A TLD refers to the last chunk of a DNS name, such as ".com"; each TLD has its own set of name servers which are responsible for their leg of the name resolution process.

The root zone (".") is to the root name servers as a TLD is to the name servers run specifically for that TLD.

A resolver that only knows about the roots will ask them where to find the servers for a TLD (.com), but that's all the roots know. To find serverfault.com, the resolver has to ask the .com name servers where to find serverfault.

Shane Madden
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  • So the TLDs knows where everything is, and the root name servers are just below them? – Wintermute Mar 01 '11 at 07:06
  • The .com name servers have information for everything under .com, but they know nothing other than that; to get to a .net address you'd have to talk to a different set of name servers. The only purpose of the root servers is to be able to find the name servers for a given TLD. – Shane Madden Mar 01 '11 at 15:43
  • @ShaneMadden I'm a bit late to join the discussion, but do you happen to have any authorized links you can post? I had an argument about this, and so far all articles I found were ambiguous about this... – EliadTech Jun 30 '15 at 09:39
  • @EliadTech About which specific part? The difference between the root servers that the gTLD servers? – Shane Madden Jun 30 '15 at 14:14
  • @ShaneMadden Yes, about that and about the root servers holding no records other then the TLDs... – EliadTech Jun 30 '15 at 19:26
  • @EliadTech What other than that did something think they're holding? – Shane Madden Jun 30 '15 at 19:27
  • @ShaneMadden Someone in my workplace argued with me that the roots hold all records that exists. I remembered that this was totally wrong, but I wanted some written proof. Also, he didn't mentioned the TLD servers at all... – EliadTech Jun 30 '15 at 19:43
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    @EliadTech Yeah, that's completely off base (and probably technically impossible, since there are a lot more DNS entries in the world than could fit in a single system's memory). Prove them wrong with https://tools.ietf.org/html/rfc2870, under 2.5: `They also MUST NOT provide secondary service for any zones other than the root and root-servers.net zones` - they're not even *allowed* to answer queries with anything other than a delegation to a TLD NS. – Shane Madden Jun 30 '15 at 21:47
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Simple. The root nameserver(s)= server the "." domain. The TLD servers serve the top level domain, DIRECTLY BELOW THE ".". So, for example, ".de" is the german country domain. DNS servers managed by DE-NIC.

The "." root name servers know the dns servers for the .DE domain and tie it all together. But they are not the top level domain servers (i.e. the servers serving the top level ".de" domain) themselves.

TomTom
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