Just as the title reads: How do I discover what nameserver is the authoritative nameserver for PTR records for a specific IP?
5 Answers
Or another way using nslookup on an address in the 216.239.32.0 subnet:
set type=ns
32.239.216.in-addr.arpa
Which will give you a list of name-servers for that reverse-lookup domain.

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@sysadmin1138 That is extremely helpful. Do you know how to perform the same on the top half of, say, a /25 that is reassigned to another party? To elaborate, the command you have here will give you the name servers for the bottom /25, but getting the name servers for the top /25 is eluding me. We tried doing it like `NSLOOKUP -type=NS 128.32.239.216.in-addr.arpa` but didn't have any luck. – Beems May 27 '15 at 22:22
Let's consider the IP 198.1.1.1
here are the different dig
commands to use to get the authoritative server (SOA) for different blocks of including this IP:
$ dig +short soa -x 198.1.1.1
$
means there is no SOA a this level (/32),
$ dig +short soa -x 198.1.1
smtdns1. hostmaster. 8 900 600 86400 3600
$
means smtdns1
is the SOA a this level (/24),
$ dig +short soa -x 198
z.arin.net. dns-ops.arin.net. 2017029249 1800 900 691200 10800
$
means z.arin.net
i sthe SOA a this level (/8).

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Sorry it's kind of obvious, it's late give me a break.
dig XX.XX.XX.in-addr.arpa. will reply with the SOA if one has been assigned.

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IF you are using Linux, try 'dig -x '.

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Please read the question again if you could. I don't want to perform a reverse lookup. I want to know who the authoritative nameserver is given a specific delegation of IP space. – CarpeNoctem Nov 29 '10 at 06:37
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dig -x would show you that, might not be the best solution but as far as I know it gives you the NS handling the address.
dig -x 8.8.8.8 tells ns1 and ns3.level3.net. dig SOA -x 8.8.8.8 will show same information as a dig in-addr.arpa. – 3molo Nov 29 '10 at 17:34
DNSStuff.com is a great place - their free tool will show this - as well as some other information for who is responsible for the IP Space - in case you need abuse contact details.
Don't worry - we all know how those late nights go...

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