same as m0oni9 said here.
most routers, if not all, wont allow an outgoing packet (from EQ client) to re-enter and be processed to the LAN (your DMZ / forwarded-to EQEmu server).
If you're lucky enough to have such router (i don't know them), ok.
Else the solution is to use hosts.txt in windows configuration files to map your External ip (as known and told by EQEMu loginservers) to internal ip (this will allow direct addressing, without round trip by the router. EQ client will ask system for external, but now system knows how to translate to internal). It's been described in one of the LAN or NAT guides.
Note the previous solution is quite unpleasant when using dynamic ip. But it's a solution. Still better than to set up an external proxy
