To Play Dungeon Siege 2 over LAN or by IP add following line to Windows Hosts file and restart the game:

127.0.0.1 dsiege2.available.gamespy.com

To customize resolution in game (menu stays ugly) and skip intros add these parameters to game shortcut:

"C:\Program Files\Microsoft Games\Dungeon Siege 2\DungeonSiege2.exe" nointro=true fullscreen=false width=1920 height=1080 bpp=32 maxfps=60