I want to play multiplayer with my brother who's in another state. We both own it on GOG.com. We tried the ICP/IP option on the game's menu but it didn't work. We weren't able to find each other's IP addresses. We made sure the address was correct as well. We used IPaddress.net or whatever.

There's also the problem that his wife won't let him use Game Ranger because they're scared of malware.

How can we play multiplayer together without Game Ranger? Thanks!!

Have you tried adding the game to the exception list on your firewall/antivirus software?