Transparent Proxying

To make the host a transparent proxy, on the m/c connected directly to the ISP, edit /etc/sysctl.conf and set net.ipv4.ip_forward to 1.
Then execute the following:
# sysctl -p
# #Use appropriate network address below
# iptables -t nat -A POSTROUTING \
-s 192.168.10.0/24 -j MASQUERADE
# services iptables save
On other hosts set their default gateway to the transparent proxy's internal IP.