Tip: Find Root DNS for a Top Level Domain

Have you needed to find the root DNS servers for a particular top level domain?

Applies to: NetScanTools Pro, NetScanTools LE, NetScanTools Basic, NetScanTools Standard (obsolete).

It’s actually pretty easy, but how you enter the top level domain makes all the difference in the world. Examples of a top level domain are: .uk, .com, .nu, .se, .ca etc.

How to do it:

1. Switch to the DNS Tools – Core tool or on older software, the Name Server Lookup tool.
2. Enter the DNS you are going use under Advanced Query.
3. Select the NS record type, you may have to go into AQ Setup or Setup to do this.
4. Enter the top level extension in the IP/host/domain entry area. The correct method is to enter the extension followed by a period: ca. or uk. or com. –if you leave off the period or put the period before the extension, the query will fail.
5. Press NSLOOKUP.

Results will look like these two examples, the first for .ca (Canada) and the second for .se (Sweden):

[Start Query]
NSLOOKUP Starting Timestamp: 02/24/11 14:49:37
Command line equivalent: "nslookup -recurse -type=NS ca."
Looking up [ca.]

DNS Name: 4.2.2.2
IP Address: 4.2.2.2

Non-authoritative answer:
ca NS nameserver = f.ca-servers.ca
ca NS nameserver = e.ca-servers.ca
ca NS nameserver = j.ca-servers.ca
ca NS nameserver = a.ca-servers.ca
ca NS nameserver = c.ca-servers.ca
ca NS nameserver = m.ca-servers.ca
ca NS nameserver = l.ca-servers.ca
ca NS nameserver = z.ca-servers.ca
ca NS nameserver = k.ca-servers.ca
ca NS nameserver = sns-pb.isc.org
Server Response Time = 0.117 seconds
[End Query]

[Start Query]
NSLOOKUP Starting Timestamp: 02/24/11 14:54:34
Command line equivalent: "nslookup -recurse -type=NS se."
Looking up [se.]

DNS Name: 4.2.2.2
IP Address: 4.2.2.2

Non-authoritative answer:
se NS nameserver = d.ns.se
se NS nameserver = e.ns.se
se NS nameserver = c.ns.se
se NS nameserver = a.ns.se
se NS nameserver = b.ns.se
se NS nameserver = g.ns.se
se NS nameserver = h.ns.se
se NS nameserver = i.ns.se
se NS nameserver = f.ns.se
se NS nameserver = j.ns.se
Server Response Time = 0.430 seconds
[End Query]

What you see in the two examples above are the authoritative name servers for the root domains.