You use your IP for loginserver if you're using a loginserver. If your just using same comp to run server and play on it, you can literally start the server right from install without changing anything...
https://github.com/EQEmu/Server/wiki/Windows-Server
About halfway down it starts with:
Setting up the Loginserver for Local LANNow, assuming you've had all of the above done, you may need to do a little manual work to configure some of your network settings to get your server to properly show up.First you will need to get your local LAN IPOpen up 'cmd' by going to Start and typing in 'cmd'Type the command:ipconfig
You will need to use this address in all of the following files
EQEmuServer: (login.ini)
EQEmuServer: (eqemu_config.json)
"loginserver2" : { "account" : "", "host" : "192.168.197.129", "password" : "", "port" : "5998" },
Uncomment the address tag and put the local LAN IP
All EverQuest Clients on the local network will need this entry: (eqhost.txt)
Restart your server using*t_start_server_with_login_server*and you should be good to go!