Running snort in IDS mode

["Plantier, Spencer" <spencer.plantier () stratech com>]

I tried running the following command and get the following error:

snort -d -h 172.30.16.0/22 -l ./log -c snort.conf
Running in IDS mode
Log directory = ./log

Initializing Network Interface hme0

        --== Initializing Snort ==--
Initializing Output Plugins!
Decoding Ethernet on interface hme0
Initializing Preprocessors!
Initializing Plug-ins!
Parsing Rules file snort.conf

+++++++++++++++++++++++++++++++++++++++++++++++++++
Initializing rule chains...
ERROR:  unknown preprocessor "flow"
Fatal Error, Quitting..
#

Any help would be appreciated. 

Spencer Plantier
System Network Administrator
 
301 Gregson Dr
Cary, NC  27511
Office 919-379-8513
Cell    919-272-8833
spencer.plantier () stratech com