Solved

Exchange and DNS

Posted on 2008-10-08
7
224 Views
Last Modified: 2012-05-05
Do I have to enter an external DNS server for exchange to use or should I us internal DNS?
0
Comment
Question by:Brent400
  • 3
  • 2
  • 2
7 Comments
 
LVL 5

Expert Comment

by:NutrientMS
Comment Utility
Internal.  Your exchange server needs to be able to see your Domain Controller.
0
 
LVL 5

Expert Comment

by:NutrientMS
Comment Utility
Sorry, to clarify that.  Your internal DNS server should have a forwarder set to your next-hop DNS server (ISP usually).  This is so all internal queries go to your Domain Controller and respond, and ones destined for external sites will be passed along to the external DNS server.
0
 
LVL 33

Expert Comment

by:Exchange_Geek
Comment Utility
Never, have your Exchange or as a matter of fact any one your internal server pointing to external DNS server - ONLY and ONLY your DNS should have forwarders set pointing to external DNS server.

Reason, your internal DNS might not have all the information in the world about DNS servers - this job gets done when you have external DNS set to respond to your queries - this is done by setting the ip address on the forwarders list.

:)
0
What Security Threats Are You Missing?

Enhance your security with threat intelligence from the web. Get trending threat insights on hackers, exploits, and suspicious IP addresses delivered to your inbox with our free Cyber Daily.

 
LVL 1

Author Comment

by:Brent400
Comment Utility
That's what I thought and that's the way it is configured.
I guess the problem is more on the DNS server.

My forwarders are set to 198.6.1.1 and 198.6.1.2. These I believe are UU.net servers. Should I be setting them to somthing else or add a few more servers? Add my ISP's?
0
 
LVL 1

Author Comment

by:Brent400
Comment Utility
The problem I'm really try to figure out is why I have a few domains that I have trouble recieving email from.
I tested an address using Smtpdiag and DNS was not resolving. I tried the Smtpdiag with the -d option and
I connected. The I tried the standard Smtpdiag with email address and /v option that failed before and it worked fine.

Did the DNS server cache the new IP from the -d option?





0
 
LVL 33

Accepted Solution

by:
Exchange_Geek earned 250 total points
Comment Utility
Look, it is always best to have the ISP DNS server listed in the forwarders list.

Also, if you are fighting the problem why few domains do not get emails from your server / delay in receiving emails - i would recommend change the SMTP Connector scope to use smart host and NOT DNS.

When you are entering smart host entry specify the ip address of your ISP in [ ] brackets. Simple.
0
 
LVL 5

Expert Comment

by:NutrientMS
Comment Utility
That should only be an issue if you were trying to send to them yes?  If you were having issues receiving from them would mean that either their SMTP server was having issues connecting to your Exchange server on port 25, or if DNS is an issue, if you run an Anti-Spam filter that has Sender Address Verification running if would not be able to resolve the senders email address.

For some testing:
On your Exchange server, open command prompt
open nslookup
type: set type=mx
type: domain.com (obviously the domain you are having issues with)
check the result (google.com      MX preference = 10, mail exchanger = smtp1.google.com)
type: exit
type: telnet <nslookup result> 25
eg: telnet smtp1.google.com 25

See if the server responds.  If this all works, then outbound SMTP shouldn't be a problem.  If it doesn't, post the response of your NSLOOKUP.

Cheers.
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

Suggested Solutions

Find out how to use Active Directory data for email signature management in Microsoft Exchange and Office 365.
Not sure what the best email signature size is? Are you worried about email signature image size? Follow this best practice guide.
In this video we show how to create a Resource Mailbox in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.: Navigate to the Recipients >> Resources tab.: "Recipients" is our default selection …
To show how to generate a certificate request in Exchange 2013. We show this process by using the Exchange Admin Center. Log into Exchange Admin Center.:  First we need to log into the Exchange Admin Center. Navigate to the Servers >> Certificates…

762 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

9 Experts available now in Live!

Get 1:1 Help Now