ok using Unrealircd type /who +s SERVER.NAME.HERE
that will tell u every user connected to that particular server .... ahh ok but what about the other servers in the network u ask ???? lol well simple even yet .... type /who -s SERVER.NAME.HERE ..... that will tell u every user connected to anyserver in the network not named the above .... u can query each and every server in the network for whos on what ..... altho im gonna guess this command would be kinda a pain in the @$$ if u have a large net .... but still its there ......
