How do I use LAN offline?

ok, so I will be out of internet range this weekend, and I wish to play a game on my PC with bots enabled, but to do so, I need to host a dedicated server. To host the dedicated server, I need to be connected to a LAN or the internet. Is their a way I can emulate a internet connection, or would plugging into a powered up (but has no internet acess) router to plug into work?