currently trying winpooch 0.5.10, which i realize hv smaller memory footprint than kerio pf v 2.1.5 and more choice.
winpooch = 29xxK - 30xxK
kpf v2.1.5 = 4xxxK - 5xxxK (somewhere around that)
d only issue is it doesn't hv any manual, n tips only done briefly. with default filter setting, u wont get anywhere. oh yes, its freeware

http://www.winpooch.com