From old notes..
Describe namran/how to become gateway here. sometime we have only one internet access but would like to have more than one device / computer/ laptop to share that same connection.
assume the one that will become gateway is a linux. kernel 2.6.* above.
enable ip forward. as root.
echo 1 > /proc/sys/net/ipv4/ip_forward
if want permanent change in /etc/sysctl.conf
and change the line that says net.ipv4.ip_forward = 0 to
net.ipv4.ip_forward = 1.
using iptables ..
export OUT=ppp0 export IN=eth0 /sbin/iptables -t nat -A POSTROUTING -o $OUT -j MASQUERADE /sbin/iptables -A FORWARD -i $OUT -o $IN -m state --state RELATED,ESTABLISHED -j ACCEPT /sbin/iptables -A FORWARD -i $IN -o $OUT -j ACCEPT
and from the other pc.. define the gateway ip.. as in eth0 in this case.