multiple instances, three nics, one box

["Zondlo, Zack" <ZZondlo () acmail aclink org>]

Anyone know how to run two separate instances of snort on one box, to
the point where they act as if on different boxes and I can get them to
show as 1a and 1b (for example) on my management box. I have 3 nics, one
outside, one inside, one for management and  I'm looking to use one
machine to monitor both sides of the firewall and want to keep
everything separate but not buy a second box.
 
Thanks,
zack