Network Scanning

Hi everyone, I been searching for a tool/software that will scan our network and display information about the hosts it found. I am more interested on the Unix servers side. I will like to find them on the network and if possible to tell me which OS they are running. Additionally, if it could tell their patch level and if it is a new server that was just turn on (red color for new type of think). I know Lisa but I don't know if they are any add on/plugin that could generate the information I need out of it? Any suggestion will be appreciated. Thanks.