Visit Jeremy's Blog.
Go Back > Forums > Linux Forums > Linux - Networking
User Name
Linux - Networking This forum is for any issue related to networks or networking.
Routing, network cards, OSI, etc. Anything is fair game.


  Search this Thread
Old 03-08-2016, 04:38 PM   #1
Registered: Apr 2012
Posts: 169

Rep: Reputation: Disabled
Question Reverse DNS purpose

Noob question incoming

Iv been reading a few articles abour Reverse DNS and PTR records but i still cant understand the logic behind the

What is the puprose of the relevant domain? Since this is an ip-to-domain resolution, why is there a domain fit to the ip address? Wouldnt a table with the delegated ip ranges be enough?
Old 03-09-2016, 08:54 AM   #2
LQ Sage
Registered: Nov 2004
Location: Saint Amant, Acadiana
Distribution: Gentoo ~amd64
Posts: 7,676

Rep: Reputation: Disabled
The purpose is to restrict spam, they want to be sure you are who you claim to be before accepting your mail. For instance, mail sent from infected Windows computers obviously does not have a valid PTR record.
Old 03-09-2016, 08:11 PM   #3
Doug G
Registered: Jul 2013
Posts: 749

Rep: Reputation: Disabled
I suspect the actual name is necessary for DNS servers to operate on PTR records using normal zone lookups, rather than creating a separate protocol for PTR lookups.

In any case, valid PTR records are provided by your isp. I know verizon automatically created PTR records for my static FIOS ip's (and if I put an infected computer on my network it could certainly send spam with valid PTR records).
Old 03-17-2016, 03:24 AM   #4
Registered: Apr 2012
Posts: 169

Original Poster
Rep: Reputation: Disabled
I understood the whole PTR thing when i realized that is an actual domain/zone and as @Doug G stated, the same protocol is used to reverse the resolve. Hence why configuring a PTR zone in bind9 you have to reverse the ip address.


dns, ptr

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
reverse dns problem - checking getaddrinfo for faile spoovy Linux - Server 8 09-23-2012 02:34 PM
[SOLVED] error "server can't find SERVFAIL" in dns server piyusharora420 Linux - Server 15 01-10-2011 01:06 AM
unable to add reverse map from to tftpadmin-desktop.bbnl.i arunrao_erp Linux - Networking 1 11-10-2010 06:02 PM
in-addr-arpa HELP!! james.farrow Linux - Networking 8 10-10-2008 02:47 AM
BIND 9 and subdomains carsten.engel Linux - Enterprise 6 07-18-2005 03:21 PM > Forums > Linux Forums > Linux - Networking

All times are GMT -5. The time now is 01:56 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Open Source Consulting | Domain Registration