I've recently configured a new Windows Server that's connected to two different networks. One interface connects to my internal system, which doesn't have any DNS, and the other connects to the firewall for internet access. I can ping the firewall gateway and Google's public DNS at 8.8.8.8 without any issues, and a tracert to 8.8.8.8 shows the right path out to the internet. However, I'm facing a problem where domain names just won't resolve. When I try to use nslookup to check google.com, it fails. Interestingly, I have another server set up in a similar manner that resolves DNS just fine. I've thoroughly checked the network settings, routes, and even the DNS entries using 8.8.8.8 and 1.1.1.1 as test resolvers, but everything appears to be in order. I'm at a loss as to what might be going on. Any suggestions?
3 Answers
You should compare the DNS settings between the functioning server and the one that isn’t working. Check if the local IP has a DNS server listed. You mentioned you’re using 4.2.2.2 and 8.8.8.8, right? That's good, but ensure no internal DNS is inadvertently in use.
Here are a few things to check out: 1) Have you set up any DNS forwarders? 2) Is port 53 open for both UDP and TCP? 3) Run 'dig' and 'nslookup' on a domain to see what results you get. 4) If you have Wireshark, check if DNS requests are actually being sent to the firewall.
Make sure on your internal interface there are no DNS settings configured. Check if it's set via DHCP or statically. Also, when you run nslookup, see which server it's trying to use for resolution. If it shows it’s timing out, that's a clear sign something's off.
Related Questions
Can't Load PhpMyadmin On After Server Update
Redirect www to non-www in Apache Conf
How To Check If Your SSL Cert Is SHA 1
Windows TrackPad Gestures