Reverse DNS

[Surreal]

Hello,

How does one go about performing a reverse DNS request to see what domain name an IP maps to?

Thanks

[slarty]

A program uses the gethostbyaddr() function in the host's resolver library.

But seriously, you probably just want to use one of the command-line DNS testing programs

"host" "dig" or the old "nslookup"

See which ones exist on your system and read their docs which will tell you how to use them.

[SirDice]

Originally posted here by Surreal
How does one go about performing a reverse DNS request to see what domain name an IP maps to?

You can do nslookup <ip> but sometimes you don't get an answer. To find out who owns an IP range it's easier to use a whois query. On most un*x machines you can use the command whois <ip>.

If you are on win9x you may need to get some tools that can do this. None of these tools are standard on win9x. On winNT/2K/XP there's an nslookup command but no whois.

You can also go to SamSpade.

[krystyna]

for a windows platform, i use idserve from steve gibson's website (www.grc.com) to do a reverse lookup.

[Tiger Shark]

A simple tracert of an ip address will resolve it if it is resolvable. Even if it doesn't resolve you will get a look at the physical region it comes from. The start digging, whois'ing etc. as mentioned above.

[bballad]

You can also do a whois an networksolutions. Sam spad would probably be your best bet though. Stay away from gibson hes culty and not very knowladagble

[nebulus200]

I recommend starting off with going to ARIN's (American Registry of Internet Numbers) web site and performing the query. At least that way, if the information is in another DB, it will kindly point you to the correct one (which in my experience, the other ones do not do, and in fact will sometimes even give you the wrong answer, like IANA reserved).

The url for the whois lookup is : http://ws.arin.net/cgi-bin/whois.pl

Place the IP in the form box and submit the query. For example, www.sony.com is 64.37.137.83.

If you submit that, you get:




OrgName: Verant Interactive
OrgID: EQ
Address: 8958 Terman Court
City: San Diego
StateProv: CA
PostalCode: 92121
Country: US

NetRange: 64.37.128.0 - 64.37.191.255
CIDR: 64.37.128.0/18
NetName: VERANT-NETBLK
NetHandle: NET-64-37-128-0-1
Parent: NET-64-0-0-0-0
NetType: Direct Allocation
NameServer: NS1.SONYONLINE.NET
NameServer: NS2.SONYONLINE.NET
NameServer: NS3.SONYONLINE.NET
NameServer: NS4.SONYONLINE.NET
Comment:
RegDate: 2000-02-04
Updated: 2000-08-29

TechHandle: VH60-ARIN
TechName: Hostmaster, Verant
TechPhone: +1-858-577-3487
TechEmail: hostmaster@verant.com

This is good for several reasons. One of them, SirDice mentioned, is that not every machine will have a name associated with it (or at least not a public one if they are running split DNS). Another couple of reasons is it gives you the nameservers that are authoritative for that zone and gives you contact information in case you are having problems.

If you are looking for IP to domain mappings, whois is a much better and more consistent place to look.

/nebulus