Dynamic IP with iptables

HAMM3R · 11-15-2005, 09:14 PM

Hey.

Can I use a dynamic IP host (like no-ip.com) with iptables?
The user i want to add has a dynamic IP, so i thought he could get a no-ip.com host, and update it when his IP changes. But will IP tables be able to detect the IP change, or just stick with the initial ip from the host when I add it?

Thanks,

HAMM3R

bulliver · 11-15-2005, 09:30 PM

You need to get your iptables script to check what the ip address is everytime it is run, rather than writing it statically in the file.

This snippet will do the trick:

Code:

IFACE=eth0
IP="`/sbin/ifconfig $IFACE | awk /$IFACE/'{next}//{split($0,a,":");split(a[2],a," ");print a[1];exit}'`"

FYI: no-ip has a Linux update client that will run as a cron task, and update your ip if it changes automatically.