A remote site underwent an ISP change and a local tech made some DNS changes that, while they work, I'm questioning. One of the issues I have found is that when I ping the name of an internal computer and expect DNS to reply with an IP address, instead of the real IP, I get an OpenDNS IP. (We use OpenDNS).
This made me want to look at DNS as a whole to make sure it's optimal before fixing this. Please review the attached. All locations were set up similar to Sites 1 & 2 and it's site 3 that was modified. Considering the details provided, I'm looking for best practices related to DC and firewall settings specific to DNS.
1. Should the primary DC DNS point only to itself?
2. Should the other secondary local DCs point only to the Primary DC for DNS?
3. Should any DC TCP/IP settings contain DNS IPs for OpenDNS
4. Should DNS1 on the firewall/gateway point to the local DNS server?