HEELPBOOK - How to test or check reverse DNS (Linux and Windows) ########################

Question: How do I test or check reverse DNS for given IP address under Linux or Windows XP/Server 2003?

Answer: Reverse DNS lookup (also known as rDNS) is a process to determine the hostname associated with a given IP address.

Typically, the DNS is used to determine what IP address is associated with a given hostname; so to reverse resolve a known IP address is to lookup what the associated hostname for it. A reverse lookup is often referred to simply as reverse resolving, or more specifically reverse DNS lookups.

The most common uses of the reverse DNS are:

* Anti-spam;

* Network troubleshooting;

* Avoid spammers and phishers using a forward confirmed reverse DNS etc.


You can use standard UNIX / Linux utilities such as nslookup, dig or hosts to find out reverse DNS of a given IP address.

######## Task: Find Reverse DNS for IP 75.126.43.235 under Linux/UNIX


$ host 75.126.43.235


Output:


235.43.126.75.in-addr.arpa domain name pointer cyberciti.org.


IP 75.126.43.235 is reverse mapped to cyberciti.org.

######## Task: Find Reverse DNS for IP 75.126.43.235 under Linux/UNIX/Windows

nslookup works under Windows and UNIX like oses:


nslookup 75.126.43.235


Output:


Server: 208.67.222.222
Address: 208.67.222.222#53
Non-authoritative answer:
235.43.126.75.in-addr.arpa name = cyberciti.org.
Authoritative answers can be found from:



############ ARTICLE INFO #############

Article Month: January
Article Date: 04/01/2013
Permalink: http://heelpbook.altervista.org/2013/how-to-test-or-check-reverse-dns-linux-and-windows/
Source: http://www.cyberciti.biz/faq/how-to-test-or-check-reverse-dns/
Language: English

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