Where can I obtain ICANN's DNS list?

Question

Suppose that I wanted to host my own DNS server based on the presumption that for whatever reason, I am unable to access ICANN's personal servers. Is there some sort of hosts file, or global DNS that I can download with the list of currently indexed and assigned addresses, and if so, where can I obtain this?

I'm pretty new to network administration, so bear with me. I haven't undertaken a task like this before. Most I've done before is screwed around with my Hosts file.

Answer 1

I think the root.zone file would provide what you are looking for. It contains all of the recognized Top Level Domains (.com, .net, .gov, .us, .ru, .cn, etc), along with the name servers IP addresses that service those TLDs.

Keep in mind the root.zone file only gets you one layer deep. As others have pointed out, DNS is a hierarchical, distributed database. There is no central list of every IP address in the world (not feasible).

Say you wanted to go to www.example.com. Your computer needs to know the destination IP address. Using the root.zone file, you would be able to identify the nameservers responsible for all .com domains. Your computer then has to ask the .com nameservers how to resolve example.com. The .com nameservers will help you identify the servers responsible for all example.com sites. Your computer then has to ask the example.com name servers for the IP address of www.example.com.

If you don't trust ICANN much, how much do you trust the registrars that are responsible for maintaining the various TLDs?

Note that in the real world, no one ever uses root.zone directly, and it can go out of date at any time. Instead, there are "root hints" servers that you can query to get this information.

You would not be the first person to have issues with ownership of the root nameservers. Alternate sets of root DNS servers exist. If you are running your own DNS server on your network, you could simply swap out your root hints with this list.

Answer 2

You mean the root.hints file? There is no database for all addresses / domains. DNS is a distributed Database.

Let's use networkengineering.stackexchange.com as an example. Assume there is a . at the end.

If your DNS server hasn’t cached the answer it will ask one of the root servers . for the com name server. After that your DNS server asks the .com name server for the stackexchange name server and then will ask the stackexchange name server for networkengineering.

If your running Linux install dig and see for yourself with dig networkengineering.stackexchange.com +trace

(It's always a good idea to have dig installed when running DNS servers).

Answer 3

The DNS is a hierarchical system, and to get your own DNS server started, it only needs to know that the DNS servers which are authoritative for the root zone (.) are a.root-servers.net, b.root-servers.net, ... upto m.root-servers.net. Of course, to actually be able to talk to these servers, at least one of their IP addresses has to be provided.

There is no need to download a list with "all" information available. The root servers will point your DNS servers to the servers which are auhoritative for the top level domain you are looking for, which in turn will point you to the DNS servers responsible for the domain you want. This process will continue until you find the server that can answer your query.

IANA provides a root hints file containing the names and ip addresses of all the root servers.

Note (some of) these 13 root servers are actually geographically distributed clusters of servers. ICANN operates l.root-servers.net.