if on windows, run command prompt, and type in:
netstat -n
itll list a bunch of ips youre using/connected to. diablo 2 is the one ending in 4000 and the server youre on is the number right before it.
the Xs below are what you want.
##.##.###.xxx.4000
to make it easier, play diablo in window mode by right clicking the shortcut icon, going to properties, and at the end of the program path "target" add in a:
-w
and apply the changes. might look something like:
"C:\Program Files\Diablo II\Diablo II.exe" -w
i have two shortcuts on my desktop. one is regular full screen and the other is window mode specifically for when im dclone hunting. also helps if youre running multiple copies of the game at the same time. hope this answers all your questions, though things may be changing in d2r. we'll have to wait and see.