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How do I locate all DNS servers?

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Last Modified: 2013-01-08
While adding a new 2008 R2 DC the message displayed during my DNS and Global Catalog choices that there were 2 DNS servers in our Domain.  However, that isn't the case.  The new DC that I'm building actually re-building was previously a DNS server, however it was properly demoted and removed from the domain before re-build.  

I ran a scan using WSPing Pro and it only shows 1 DNS server.

So is the Windows message and error or do I have a rogue DNS server?  How do I verify?
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costanosNetwork Engineer

Commented:
What shows up when you run NSlookup in CMD?
Perhaps you can try doing it with nslookup?
nslookup
Set type=NS
contoso.com

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Top Expert 2013

Commented:
You can use nslookup


nslookup
set type = NS
Your domain name

Look on the name servers tab in DNS and look for entries for the old box in DNS.

Thanks

Mike
J.R. SitmanIT Director

Author

Commented:
when I run NSlookup I get "default server unknown 172.17.1.30".  which was the old DNS server that was removed but has now been added back in with the same IP and it is now a DNS server again
J.R. SitmanIT Director

Author

Commented:
if I run it from the new DNS server I get the same results but with the ip address of the other DNS server.
Is your DNS configuration of that server correct?
Have you verified that this DNS server is functioning?
What is your ipconfig on your workstation like? are you able to resolve (forward and reverse) the name/IP of that server from your workstation?
If you can't, then you need to address that issue to make sure that is working.
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Top Expert 2012

Commented:
make sure you have setup DNS correctly in your env follow below best practices

Best practices for DNS client settings on DC and domain members.
http://abhijitw.wordpress.com/2012/03/03/best-practices-for-dns-client-settings-on-domain-controller/

Also run dcdiag /test:dns to check the DNS issue on the dc
J.R. SitmanIT Director

Author

Commented:
DNS settings verified.
Yes DNs is working.  No problems
ipconfig from the workstation shows the proper DNS servers and DHCP server

So as far as I can tell there isn't a problem, that I can see
J.R. SitmanIT Director

Author

Commented:
OK.  I'll post later.  Got to get to a meeting
J.R. SitmanIT Director

Author

Commented:
when I run dcdiag /test:dns I get unrecognized command.  I get the same thing if I run ipconfig /flushdns
DrDave242Principal Support Engineer
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Commented:
You get "unrecognized command" when you run ipconfig /flushdns?  If that's the case, something's gone very wrong.

Wait, you're not still in nslookup, are you?  If so, type exit and try again from the normal command prompt.
Also, when you're doing these commands, you might want to open the command prompt with elevated privileges.
ipconfig /flushdns will work with normal privilege, but, ipconfig /registerdns won't.
J.R. SitmanIT Director

Author

Commented:
yep was still in nslookup.  Attached are the results.  It is trying to find a DNS server that has been gone at least 2 years spcala02
dnsfail.jpg
DrDave242Principal Support Engineer
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Commented:
Open the DNS console on one of your DNS servers, right-click your domain's forward lookup zone, and select Properties.  What's listed in the Name Servers tab?  (Check any other forward lookup zones you've got too.)
J.R. SitmanIT Director

Author

Commented:
There are 3 forward lookup zones.  see attached.  In all three the only DNS server listed is the one that was removed two weeks ago and then added back today.  I used the same server name and IP address when adding it back to the domain
dnsforward.jpg
J.R. SitmanIT Director

Author

Commented:
I just did ipconfig /all from a workstation and it has all the correct servers. DNS/DHCP
Principal Support Engineer
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Commented:
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J.R. SitmanIT Director

Author

Commented:
yep it was.  I'll rerun the test.
J.R. SitmanIT Director

Author

Commented:
The initial rogue DNS server is gone but the other errors are still there.  I'll award the points for this and open a new case.  Please watch for it.  You obviously know what you're doing.

Thanks
J.R. SitmanIT Director

Author

Commented:
thanks
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