Found a problem!

when me and my bro were playing online togheter he tried to connect to my server so he went to SBR2 master server status and my server was up with a diffent I.P adress it was not mine so he tried connecting but it sat there and all it said was *contacting server* so i said "hey thats not my real ip adress its showing" so i typed in mine in is srb2 game and it connected fine...How come the master server shows the wrong I.P? :|