I don't mean to go in circles here, apologies if I am. Like I said at the start, I'm still new when it comes to routing, so I'm just trying to wrap my head around the issue thoroughly rather than just say "ok!" and potentially misconfigure something critical. Thanks in advance for dealing with me.
Regardless of the DNS trick being used or not, it's to my understanding that I will still need a port forward configured on my router to allow WAN requests to make their way into my network and reach my server. Configuring this forward is my main concern, more than how I plan on contacting said machine.
I've seen tutorials like this one, (Which it looks like you contributed to, actually!) where they set up a network very similarly to mine. The port forwards section specify to set the internal zone to "DMZ", and the internal IP to the machine in said zone. This is the part that confuses me the most. When I try doing the same with my SERVER zone, configured similarly, my port forwards don't work whatsoever. However, when I modify the forward to use the same internal IP and but my LAN internal zone, it does work. Why is this?
Maybe this phrase is what needs to be expanded upon for me to understand. Why when I set the forward's internal zone to my server zone is it unable to contact anything inside the SERVER vlan? I assume it's a firewall config issue more than anything.