[LoginServer]
loginserver=eq2emulator.net
loginport=9100
worldname=Axel
worldaddress=67.187.170.125
internalworldaddress=192.168.1.100
worldport=9000
locked=false
These settings allow connection from the internet and from the local network. The problem is that when people connect from both sources one of the game clients crash.
This is the error

So far I haven't been able to find a setting that allows stable connections for both internal and external connections.

Seems that the server can't support more then one connection at a time.

It can, it is just that the client position updates are buggy right now and most of the time crashes other clients.

Multiple connections do work, just not all the time.