The information you provided may be good for someone only wanting to play within their own LAN, but here is a quote from the Original Poster in the first post of this thread:
Originally Posted by Sourdough35
It runs fine, but I also want to set it up so a small number of people can connect from other sources, but I don't want to open it up as a server everyone can connect to.
If he uses 192.168.x.x address space, others outside of his LAN will never be able to connect as those are not publicly routed IP addresses as I am sure you are aware. So, the information you provided is not relevant for this particular thread. I think you may have just missed that part of his post and thought he was trying to setup a LAN only server like you run.
And yes, the best solution is to use dyndns.com with EQEmuLoginServer or to just make it a public server and restrict access, which is probably the easiest route to go.