• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 276
  • Last Modified:

Can someone check this DNS config please?

(haven't submitted these changes yet)

MX Records:
  dissolvedz.com. IN MX 10 www.dissolvedz.com.

A Records:
  dissolvedz. IN A  68.34.76.5
  www.dissolvedz.com. IN A  68.34.76.5

CNAME Records:
  mail.dissolvedz.com. IN CNAME  www.dissolvedz.com.


What I'm trying to do:
My public IP address (home address) is 68.34.76.5.  I am hosting a website. I also have an internal mailserver.
Do my records look ok?

(note, i wasnt sure on the CNAME stuff. I just made a "mail.dissolved.com" out of nowhere. It is not a subdomain. Just trying to use it as an alias)
thanks
0
dissolved
Asked:
dissolved
  • 5
  • 5
  • 2
  • +1
1 Solution
 
syntaxmishapCommented:
dissolved -

Your dns records look fine.

One thing you should know when running a mail server, is that the PTR record for your IP address will point to a Comcast hostname, different from your domain. New spam filtering software will sometimes see this and assume that you are spam and not let your mail through. Not a life or death situation, but it can be a nuisance.

syntaxmishap
0
 
dissolvedAuthor Commented:
Ok so my CNAME is all set then?  Like I said, "mail.dissolvedz.com" isnt a name I bought. I'm trying to see if I can use it an a CNAME alias (guess we will find out. I'm going to do a c:> ping mail.dissolvedz.com and see what happens)

About the PTR record...could you elaborate?  I'm guessing you mean the problem is on Comcast's side?  My host name on comcast is something like  townsend01.de.comcast.net. A reverse lookup would yield  68.34.76.5. How will this cause conflict with my mx records?

Thanks!
0
 
syntaxmishapCommented:
dissolved -

Yep, your CNAME record is fine. This will just point mail.dissolvedz.com to www.dissolvedz.com. This can be a bit more tricky when you have 10 mail servers, and 5 web servers under one domain. However, with a single computer / server, it's nice and simple.

The PTR record is also known as a reverse DNS entry for an IP address. Just like you can turn the domain name into an IP address, the PTR record works the other way around.

Some mail servers, when accepting a piece of mail from your server, will see that it came from dissolvedz.com, and the IP address 68.34.76.5. To verify that you are who you say you are, they will lookup the PTR record for 68.34.76.5 and see if it resolves to dissolvedz.com. If it doesn't, then your email may look suspect. In this case, they would see that it resolves to townsend01.de.comcast.net and not dissolvedz.com.

In the case of Earthlink, for instance, you would get an email back and have to type in a word stored in an image on their server to verify that you are a real person, etc. Most spam filter software evaluates many variables from the email, such as pattern matching on the contents, and other things - so this alone is usually no reason to raise a red flag.

If this is for personal use, then you shouldn't have any problem.

If you have a server hosted at a server farm or a T1 line or something, then you can get the owner of the IP block to change the PTR record from the IP address to your domain name. With a standard ISP, like Comcast for instance, they won't let you do this to the best of my knowledge.

To give you an example, my company, which sends out around 500 email order confirmations per day, recently moved to a new hosting facility and we were without a PTR record for a couple days. In all of that, we only had 3 or 4 order confirmation emails get returned.

In short, it is something that you should at least be aware of if you have any problems with spam filters, but not something that will likely cause you any troubles.

syntaxmishap
0
Windows Server 2016: All you need to know

Learn about Hyper-V features that increase functionality and usability of Microsoft Windows Server 2016. Also, throughout this eBook, you’ll find some basic PowerShell examples that will help you leverage the scripts in your environments!

 
lrmooreCommented:
Bookmark this web page and try your domain name.
http://www.dnsreport.com/

ERROR: The parent servers say that the domain dissolvedz.com does not exist
0
 
dissolvedAuthor Commented:
great link lrmoore!
0
 
marcin79Commented:
> dissolvedz. IN A  68.34.76.5

shouldn't it be a

dissolvedz.com. IN A  68.34.76.5
or
@ IN A  68.34.76.5

regards
Marcin
0
 
dissolvedAuthor Commented:
Marcin, are you referring to MX records or A records?
Thanks!
0
 
marcin79Commented:
a records
0
 
marcin79Commented:
you posted
A Records:
  dissolvedz. IN A  68.34.76.5

and if your server will be dns which is serving this domain (have an SOA record)
it should be (IMHO) what i posted above

the rest of entries looks ok

regards
Marcin
0
 
dissolvedAuthor Commented:
I gotcha

dissolvedz.com. IN A  68.34.76.5
or
@ IN A  68.34.76.5


the "dissolvedz" was missing the ".com" after it

By the way, what does the  "@" symbol do above?

Thanks
0
 
marcin79Commented:
linux dns server (bind) replaces sign '@' with the domain name for which the zone file is for so if you have zone containing soa record for dissolvedz.com it will be replaced by dissolvedz.com

hope that helped

regards
marcin
0
 
dissolvedAuthor Commented:
thanks a lot
0
 
marcin79Commented:
no problem
if you could post me some feedback

regards
Marcin
0

Featured Post

 The Evil-ution of Network Security Threats

What are the hacks that forever changed the security industry? To answer that question, we created an exciting new eBook that takes you on a trip through hacking history. It explores the top hacks from the 80s to 2010s, why they mattered, and how the security industry responded.

  • 5
  • 5
  • 2
  • +1
Tackle projects and never again get stuck behind a technical roadblock.
Join Now