Split Horizon on Windows

Are you currently running an authoritive nameserver for a domain on your windows dns servers?  If no, why are you even bothering with split horizon?

Then again I'd argue that the author of that github wiki doesn't even truly understand what split horizon actually is.  He's just talking about conditional forwarding thinking that is split horizon when it's not.

Haha I just realized that's one of the creators of NextDNS, too.  I'll give him a pass.  I've built multiple ISPs from the ground up myself, and what he's talking about is not technically split horizon.

Split horizon is more meant for serving the same domain internally and externally and having only internal viewable resolvers while external queries do not see those from the authoritive (SOA) servers for a domain.  Like for instance ibm.com's name servers are going to have a ton of internal hosts that are resolvable only on their networks (That is one view/horizon) while all external queries only get their public hostnames (The other view/horizon).  If you're not SOA, it's technically just conditional forwarding. :)

In your case, just setup the domain on your nameservers and it'll resort to that before it goes to it's forwarder.  The caveat to that is you have to mirror the external domain name hostnames on your zonefile otherwise they won't resolve, because your nameserver think's it is authoritive.  If that doesn't work for you, you're left with editing your hosts file on the PC.