Ok i have setup my comp as a private Lineage 2 server. It runs good and i can connect and get in game but other people can't connect. Even with disabled firewall and i don't use a router.

here is the server.cfg

# This is the server configuration file. Here you can set up the connection for your server.
# Usually you have to change the ExternalHostname option to
# - 127.0.0.1 (if you want to play alone / testing purpose)
# - LAN IP* (if you want to play from another computer in the network)
# - WAN IP** (if you want to play with friends over internet)
# - Questions? => http://l2j.sourceforge.net
#
# * = If you want to get your LAN IP, simply choose "Start" => "Run..." then type "cmd" => "ipconfig"
# **= If you want to get you WAN IP, visit http://www.whatismyip.com
# ===================================================================================================

# Bind ip of the gameserver, use * to bind on all available IPs
GameserverHostname=*
GameserverPort=7777

# This is transmitted to the clients connecting from an external network, so it has to be a public IP or resolvable hostname
ExternalHostname=24.71.10.121

# This is transmitted to the client from the same network, so it has to be a public IP or resolvable hostname
InternalHostname=24.71.10.121


# Bind ip of the loginserver, use * to bind on all available IPs
LoginserverHostname=*

# Useable values: "true" - "false", use this option to choose whether accounts will be created
# automatically or not. If not, you have to put it in the logins.txt in the data folder
AutoCreateAccounts=true

# Define how many players are allowed to play simultaneously on your server.
MaximumOnlineUsers=20

From everything i have read this is the proper setup. maybe for external i have to use my gateway IP??

Any ideas are most welcome