I need to setup a intrusion detection system for about 15 servers (Windows 2003 and MAC OS X Server). The problem is, I really don't know much about IDS. I would like to use free software. I have heard of SNORT, and from what I can tell, it monitors packets on your network. I was wondering, can it also monitor logs? Anyway, I was just wondering what everyone else out there uses. Any help is appreciated, thanks.