How to REALLY home share in iTunes?

Well, since aple thinks home sharing is just having 2 mac's connected and with the option in ON, they think is that simple, well, no, the thing i wante to ask is, the last time, touching IP settings in my macbook (to share with an imac) i put and ip from the imac and it works, well, now, i don't remember wich ip setting was and i'm not sure by any mean, so, if someone has done this before (that isn't me of course) could you help me? (when i use my imac in bootcamp Windows 8, it works without problems).