I have software which needs to run as a non-root user, but needs to listen on port 80 and 443. With iptables, this isn't all that difficult:sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 8080sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 443 -j REDIRECT --to-port 8080Though this is simple, how should I persist it to take effect on boot? I tried iptables-save, but this didn't seem to work. 
Local port forwarding automatically configured on boot?
ubuntu;iptables;port forwarding
The standard method for restoring iptables rules on boot for Debian-based systems is using a pre-up rule in /etc/network/interfaces. First you need to save the current rules to a file:iptables-save > /etc/iptables.rulesIn the block for the relevant interface in /etc/network/interfaces add:pre-up iptables-restore < /etc/iptables.rulesOther methods, such as loading via network-manager can be found on the ubuntu wiki.