I'll confess I'm confused about whether DNS setup and routing protocols are considered on or off topic here.
Could moderators and similar clear this up?
Routing protocols (OSPF, BGP, EIGRP, etc) are definitely on topic and likely this is the best site on the SE network of communities to answer such questions.
As for DNS, DHCP, NTP and other similar services, this was debated early on in the life of this community (see here for example). On one hand I personally believed there is room for such topics here and spoke to that position, but on the other felt that these were also topics that overlapped with larger and more established communities on the SE network, such as ServerFault. General DNS question were likely to get faster and more diverse set of answers from a community such as ServerFault.
In the end, the community tended to agree with the position that such topics were best handled by other SE network communities and should be off topic here so that we could direct such questions to those communities. While I may personally disagree with that position and feel that overlap with other sites isn't a negative, the community has made it's decision and as a moderator I will continue to enforce the position (unless the community decides to change this position at some future time).
So DNS/DHCP/NTP configuration as it applies to configuring a on topic network device are on topic. However, general DNS/DHCP/NTP service related questions are not.
Routing protocols (RIP, OSPF, EIGRP, BGP, etc.) are very much on-topic for Network Engineering.
DNS is not a routing protocol, it is an application-layer protocol, and protocols above OSI layer-4 are off-topic for Network Engineering, but the configuration of something like the DNS server built into an on-topic device may be on-topic as a feature of the device. A stand-alone DNS server is off-topic, and it can be asked about on Server Fault.