yup... close everything except LFS... do not join a server... open the command line and type "netstat -n" this will show you all connections from your machine... now connect to a server, repeat, and viola the IP that wasn't there before is the IP of the server...
Vain> if LFS you try to connect even via direct IP and there is an active internet connection, LFS checks master server... so: no go for crackers... without an account on the masterserver you can't connect...