Here's an example configuration file which shows off some of the more complex features of the file format:
# Cookies'n'stuff. cookie Hello_World listen 17003 client allow stkitts.cl.cam.ac.uk set do_fork on #Acls global allow 128.232.0.0/255.255.240.0 from 1200 - 1600 global allow 128.232.0.0 netmask 255.255.240.0 global allow epona.ucam.org global allow maui.al.cl.cam.ac.uk global allow maui.nt.cl.cam.ac.uk global allow uist.cl.cam.ac.uk # Redirects #redirect stkitts.cl.cam.ac.uk port 12000 to 131.111.129.173 # port 27910 deny maui.nt.cl.cam.ac.uk redirect stkitts.cl.cam.ac.uk port 12004 to quake-1.games.group.cam.ac.uk port 27910 allow uist.cl.cam.ac.uk delay 90 #redirect stkitts.cl.cam.ac.uk port 14000 to quake-1.games.group.cam.ac.uk port 27910 on epona.ucam.org redirect stkitts.cl.cam.ac.uk port 12004 to 131.111.129.174 port 27910 redirect stkitts.cl.cam.ac.uk port 12000 to 131.111.129.173 port 27910 redirect stkitts.cl.cam.ac.uk port 12001 to 131.111.129.173 port 27910 delay 210 redirect stkitts.cl.cam.ac.uk port 12002 to 131.111.129.173 port 27910 delay 90+90 redirect stkitts.cl.cam.ac.uk port 12003 to 131.111.129.173 port 27910 delay 90 redirect stkitts.cl.cam.ac.uk port 14000 to quake2.demon.co.uk port 27910 redirect stkitts.cl.cam.ac.uk port 16000 to quake2.demon.co.uk port 27910 deny maui.al.cl.cam.ac.uk/255.255.240.0 from 0 - 1024