Arashi_Kanashimi

I've finally got Tekkit, but constantly have to unplug the internet to stop it using it. Even when I'm in singleplayer, it still uses internet, and since I don't have uncapped, this is a big problem. So why does it do this, and can I change some setting to stop it? Also, my brother and I want to play Tekkit on a server, and we could run our own. Our vanilla server doesn't use actual international internet (I think it uses LAN). Will a Tekkit server do the same, or will it use normal internet anyway?