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How can I Fix DNS entries

handyjay
handyjay asked
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Last Modified: 2012-06-21
I have been given the task of fixing out DNS server... I need to promote this DC to a new server so I want to fix everything first.  I am learning as I go along...

First question I have is based on the image attached.  There are duplicate Host entries pointing to a single IP address.  Some of the Host entries do not even exist anymore.

I am not sure if the last person set this up manually or dynamic.  I'm wondering if this could cause problems and how to fix it.  I was also wondering if there is a Support Tool I can use to automatically fix DNS entries or tell me what needs to be fixed before I start the DC promotion process.


DNS-Forward.JPG
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Justin OwensITIL Problem Manager

Commented:
You can have multiple Host(A) records pointing to the same IP address without issue.  What you cannot have without issue is multiple IP address pointing to the same hostname. :)  Those records could be manual or dynamic, depending on how they were set up.  Have you looked to see?  As far as DNS health, your best friend is

DCDIAG /test:DNS

Other useful tools:

NSLOOKUP
DNSCMD

Have you any experience with these?

DrUltima

Author

Commented:
I do not know how to tell if it was setup manual or dynamic.... can you tell me how?  I assume dynamic as the person pretty much always took the easiest route in setting up computers systems.

As far as tools, I have not used them but am currently watching some videos about AD troubleshooting techniques.

I have attached another screen shot.  The first is the Forward lookup and the new one is the reverse lookup.

Look at IP xxx. 16 (for example) the forward and the reverse do not match up.

Also IP .7 on the reverse does not exist in the forward.

Both of these IPs have caused issues with our firewall software and seems to be the reason I was searching for issues in the wrong place.

Is there a safe way to "reset" it and let it fix itself... or will this cause more issues?
dnsReverse.JPG
ITIL Problem Manager
Commented:
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Author

Commented:
These sound like they will help me with my issue.

I was wondering (see new screen shot), do you have any idea why I don't have a "General" tab as the Microsoft instructions indicate I should navigate too?
DNSCapture.JPG
Justin OwensITIL Problem Manager

Commented:
That screenshot is from Server 2003, right?  What is the article you are referencing?  That looks right to me, but I don't have a Server 2003 with DNS installed on it to check.

DrUltima

Author

Commented:
Yes it is 2003.  The article I am refereing too is the Allow dynamic updates.  The instructions are pretty simple... just dont see "General" tab.

I was going to use Command line, but I wanted to see what it was set now first, just to see where I stand before I make a change.


Allow dynamic update instructions:

1. Open DNS.
2. In the console tree, right-click the applicable zone, and then click Properties.
3. On the General tab, verify that the zone type is either Primary or Active Directory-integrated.
4. In Dynamic Updates, click Nonsecure and secure.


Justin OwensITIL Problem Manager

Commented:
Gotcha... You need to have the Zone highlighted, not the root of your domain, as this picture indicates... :)

Author

Commented:
Thanks, scavaging was off.
Justin OwensITIL Problem Manager

Commented:
Glad you found that and it is working for you.  If you have future issues related to this, you can always come back to this Question and "Ask a Related Question".  Doing so will notify all experts who are monitoring this thread as well as any in the Zones you place your new Question.

Best of luck!

DrUltima
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