LinuxQuestions.org
View the Most Wanted LQ Wiki articles.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Server
User Name
Password
Linux - Server This forum is for the discussion of Linux Software used in a server related context.

Notices

Reply
 
Search this Thread
Old 12-21-2010, 01:08 AM   #1
hydraMax
Member
 
Registered: Jul 2010
Location: Skynet
Distribution: Debian + Emacs
Posts: 467
Blog Entries: 60

Rep: Reputation: 51
DNS: A Record and PTR Record


I'm setting up my first e-mail server (Gentoo Linux w/postfix). The server is a self-managed box I rent from a company that sells rack space. But my name servers and registration are provided by another company.

Anyway, I'm going through an old copy of "The Book of Postfix" and trying to make sure my DNS configuration is all correct. The book says that my A RECORD should match my PTR RECORD, or there could be problems communicating with some e-mail servers.

I can dig my server's fqdn just fine, which is in the domain I bought from the company that handles the registration. However, if I dig -x to do the reverse lookup for the ip address, instead of that fqdn, I get an internal fqdn made up by the company that is taking care of my self-managed computer.

/As far as I know/ this hasn't caused any problems sending or receiving e-mail. But is this an issue that will need to be resolved? And if so, who should I be talking to? (My name server provider or my rack-space provider?)
 
Old 12-21-2010, 09:33 AM   #2
AlucardZero
Senior Member
 
Registered: May 2006
Location: USA
Distribution: Debian
Posts: 4,613

Rep: Reputation: 518Reputation: 518Reputation: 518Reputation: 518Reputation: 518Reputation: 518
It should be resolved, yes, because if your forward and reverse DNS do not match your server will be trusted less (the non-matching is typical of cheap or home setups). I believe you need to talk to the company that is taking care of your self-managed computer.
 
Old 12-21-2010, 11:43 AM   #3
Noway2
Senior Member
 
Registered: Jul 2007
Distribution: Ubuntu 10.10, Slackware 64-current
Posts: 2,124

Rep: Reputation: 776Reputation: 776Reputation: 776Reputation: 776Reputation: 776Reputation: 776Reputation: 776
My ISP will allow you to change the reverse DNS if you are a business grade customers with static IP addresses but residential customers are stuck with the default naming. If you are running a mail server on a residential account, one way around a lot of problems is to relay your mail through your ISP's SMTP server. Mail still originated and is received by your server (BTW, it doesn't show as being from your ISP domain) it is just that their SMTP becomes the first hop along the path rather than directly on to the Internet.
 
Old 12-21-2010, 12:50 PM   #4
Dani1973
Member
 
Registered: Dec 2010
Distribution: Debian testing
Posts: 148

Rep: Reputation: 16
If the server only handles incomming mail then this shouldn't be a big problem.

Like AlucardZero stated, the reverse lookup is used to see if your server can be "trusted" and sometimes this configuration needs to be accurate to get your IP cleared from blacklists, but this doesn't mean that no other servers will not trust your server at all!
If I am not mistaken, spam software will compare the ptr and the mx record to see if the server they are receiving mail from can be trusted, if they don't match the mail is subject to get a higher score.

ptr records are handled by the ISP, so in this case the company where you are renting the server/rackspace.
 
Old 12-21-2010, 10:28 PM   #5
hydraMax
Member
 
Registered: Jul 2010
Location: Skynet
Distribution: Debian + Emacs
Posts: 467
Blog Entries: 60

Original Poster
Rep: Reputation: 51
Went back to my rackspace provider's website, and found out that they had a control panel just for setting rDNS records. Problem solved!
 
  


Reply


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
DDNS record and a static PTR record mou5e Linux - Networking 2 01-22-2008 01:16 AM
PTR record OTIM Linux - Server 3 11-22-2007 12:16 PM
Creating A record and PTR record daemonkl *BSD 3 10-03-2007 04:50 PM
what is the actual use of PTR record in DNS ZAMO Linux - Server 1 04-12-2007 01:15 AM
How to format DNS PTR record ? pcom Linux - Networking 2 07-01-2004 11:59 PM


All times are GMT -5. The time now is 10:49 PM.

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