Cisco Umbrella & DNS Forwarders

[IamSamSaul]

Hi there, 

I have configured Cisco Umbrella DNS servers as DNS Forwarders on my domain controller. Some of internal servers (DNS server = my domain controller) are working while a few servers can't resolve external domain names.

I hope someone got an idea what might be the reason and how I can troubleshoot this issue.

Thanks.

Regards,

Sam

[Rob Ingram · Accepted solution]

@IamSamSaul 

So all servers are configured to use the same internal DNS servers (the Domain Controllers), but some can resolve external DNS domains and others cannot?

Can you run an nslookup from a working server and another from a non-working computer, just to compare the difference.

Are there any hits in the umbrella console, and the request is blocked?