Hi, I have found this page useful when setting up squid and iptables.
Controlling_Web_Access_with_Squid
Port_Forwarding
Code:
# File: /etc/sysctl.conf
#---------------------------------------------------------------
# Enable IP routing. Required if your firewall is protecting a
# network, NAT included
#---------------------------------------------------------------
net/ipv4/ip_forward = 1
these pages are updated....lately, watch your versions....
hope this helps
regards Glenn