LINUX ADMINISTRATION NOTES & CODE SNIPPETS

Lets say that we would like to do port forwarding from our network interface eth0 on port 23  (telnet) to socket 10.0.0.1:23 (ip address:port):
iptables -t nat -I PREROUTING -p tcp -i eth0 –dport 111 -j DNAT –to 10.0.0.1:23
other example:
to do port forward from eth0 on port 456 to 192.168.0.1:788
iptables -t nat -I PREROUTING -p tcp [...]

Filed under: Administration, Networks, Security | No Comments »

Sharing internet connection with NAT (network address translation) can be easy as running commands:
iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE
echo 1 > /proc/sys/net/ipv4/ip_forward
where ppp0 is your external interface.

Filed under: Administration, Linux, Networks | No Comments »