DNS Forwarding Issues

[seahorse]

Hi all

 

We currently have a dual DNS Server setup where by a primary and secondary DNS both have DNS Forwarders setup.

The vast majority of urls accessed have no issues at all, however one in particular does not resolve to an I.P address as long as either of the internal DNS servers are configured on a client either with DHCP or statically.

 

If I configure a client with a static DNS server address which is that of any of the forwarders the site is accessible.

It simply will not forward to the forwarding addresses via the internal DNS servers and only relies on its own database which clearly does not resolve to anything.

 

Ping

"Ping request could not find host ... Please check the name and try again."

 

Tracert

"Unable to resolve target system name ..."

 

NSLookup

Non-existent domain

 

Tee same goes from either a client or any of the DNS servers.

The site isn't being blocked by any filtering and I have tried whitelisting the site for good measure anyway.

 

The host network adapters are configured the way they should be as far as I can tell according to serverl online sources I've crossed referenced to make sure.

Both server formerly had a tertiary DNS server configured against the host adapter which has since been decommissioned but removing this had no affect.

 

DC1

Host NIC Adapter:

Primary DNS=Secondary DNS Server Address

Secondary DNS=127.0.0.1

IP/6 disabled

 

DC2

Host NIC Adapter:

Primary DNS=Primary DNS Server Address

Secondary DNS=127.0.0.1

IP/6 disabled

 

DNS configuration on both servers

Forwarders:

Primary=8.8.8.8

Secondary=8.8.4.4

 

"Use Root Hints if no forwarders are available" is ticked.

Standard Root Hints configured as default, no extras.

 

Any suggestions would be greatly appreciated and I'm happy to dig about and take criticism of any configuration settings as I wasn't the one who set these up.

 

Thank you

Edited August 5, 2019 by seahorse

[psydii]

What zones do your DC/DNS server host? Is it possible that the host you are trying to resolve has some sort of name collision with a host in your local DNS?

 

On the configuration of your severs:

 

"The inclusion of its own IP address in the list of DNS servers improves performance and increases availability of DNS servers. However, if the DNS server is also a domain controller and it points only to itself, or points to itself first for name resolution, this can cause a delay during startup. For this reason, use caution when configuring the loopback address on an adapter if the server is also a domain controller. The loopback address should be configured only as a secondary or tertiary DNS server on a domain controller." https://docs.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2008-R2-and-2008/ff807362(v=ws.10)

 

So that config you have look fine to me.

[seahorse]

Thank you for the prompt reply psydii

I had a feeling it would be down to a hot record or zone but not until this very moment was it staring me in the face.

We have a local intranet site which has been setup as a forward lookup zone in DNS. We recently had an issue whereby the address had to be changed so this may be the reason.

Essentially the zone is labeled "info" and the domain name reside in it as well as Host (A) records for www.

I'm not quite sure why it was ever setup this way but the only change as far as I know was in the domain name part when google recently blacklisted the domain.

 

It would appear that no domain names ending in .info work.

 

So now I know the root cause but I don't know quite how to resolve it without breaking our intranet.

 

Essentially we just need a specific url to point to a specific SharePoint website.

[kmount]

Hello,

 

I'd remove the zone called "info" and make a new zone called whateveryour.sharepoint.site.info is (i.e. a zone for the very specific record of your Sharepoint site)

 

This will mean info is treated as normal but your very specific url zone will work as you wish

[seahorse]

Thank you.

I'll take it under advisement but this is most likely what I'll do. I've looked at this setup myself recently and knew something wasn't quite right.