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external dns of a server

snyperj
snyperj asked
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Where would I look to see if a server on our network has an external DNS.  

If it does have an external DNS, how could I tell if it is restricted to only certain IP ranges?

Windows 2003 Server

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it_saigeDeveloper
Distinguished Expert 2019

Commented:
By external DNS, do you mean that the server itself looks at an external DNS source (via the Network Card Settings for Primary and Alternate DNS servers) or that the server is providing DNS externally?

-saige-
Seth SimmonsSr. Systems Administrator

Commented:
Where would I look to see if a server on our network has an external DNS.  

you can run ipconfig /all and you will see the DNS servers it is configured to use
or look at the TCP/IP properties of the interface; click on the advanced button and the DNS tab

If it does have an external DNS, how could I tell if it is restricted to only certain IP ranges?

if you can ping the server but queries to it fail, it's possible
though if it is using something like google or your ISP there shouldn't be a restriction for queries

Author

Commented:
I should have been more specific, what I am trying to determine is if the server can be reached from outside of our network.  I believe it can be, but I am having trouble finding the info I need to be able to connect to it externally.
Developer
Distinguished Expert 2019
Commented:
If you believe that your server is publishing DNS externally then look for outbound traffic over port 53.  To see if your firewall is indeed publishing 53, you can use Shields Up at grc.com in order to do a scan of the ports.

-saige-
HaroldNetwork Engineer

Commented:
I should have been more specific, what I am trying to determine is if the server can be reached from outside of our network.  I believe it can be, but I am having trouble finding the info I need to be able to connect to it externally.

If Remote Access is enabled and your server and port forwarding(NAT) the public IP to the private(assuming your IP is private on server), then you could access via RDP session. Default port for RDP is 3389, unless you change this, which is a good idea for security.

Or you could use something like team viewer to access.

Author

Commented:
Thanks- this is what I did