Save changes to iptables

I've got iptables running, as I can use the following command...

sudo /sbin/iptables sudo /sbin/iptables -t nat -I PREROUTING -p tcp --dport 80 -j REDIRECT --to-port 8080

but I cant do....

service iptables save iptables: unrecognized service

How do I actually save these changes as the mapping stops when I restart the server?

Thank you.

As far as I know Ubuntu uses UFW in the latest version, so most likely it doesn't have a SysV init script for iptables. If you don't feel comfortable with UFW, you may use sudo iptables-save > /etc/iptables.rules to store your current rules and then invoke sudo iptables-restore < /etc/iptables.rules from rc.local (for example) to restore the rules on startup.

Or, you can add your own init script for iptables as specified here:

#!/bin/sh -e
### BEGIN INIT INFO
# Provides:          iptables
# Required-Start:    mountvirtfs ifupdown $local_fs
# Default-Start:     S
# Default-Stop:      0 6
### END INIT INFO

# July 9, 2007
# James B. Crocker <[email protected]>
# Creative Commons Attribution - Share Alike 3.0 License (BY,SA)
# Script to load/unload/save iptables firewall settings.

PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin"

IPTABLES=/sbin/iptables
IPTABLES_SAVE=/sbin/iptables-save
IPTABLES_RESTORE=/sbin/iptables-restore

IPTABLES_CONFIG=/etc/iptables.conf

[ -x $IPTABLES ] || exit 0

. /lib/lsb/init-functions


case "$1" in
start)
    log_action_begin_msg "Starting firewall"
        type usplash_write >/dev/null 2>/dev/null && usplash_write "TIMEOUT 120" || true
    if $IPTABLES_RESTORE < $IPTABLES_CONFIG ; then
        log_action_end_msg $?
    else
    log_action_end_msg $?
    fi
        type usplash_write >/dev/null 2>/dev/null && usplash_write "TIMEOUT 15" || true
    ;;

stop)
    log_action_begin_msg "Saving current firewall configuration"
    if $IPTABLES_SAVE > $IPTABLES_CONFIG ; then
        log_action_end_msg $?
    else
        log_action_end_msg $?
    fi
    log_action_begin_msg "Flushing ALL firewall rules from chains!"
    if $IPTABLES -F ; then
        log_action_end_msg $?
    else
        log_action_end_msg $?
    fi
    log_action_begin_msg "Deleting ALL firewall chains [Warning: ACCEPTING ALL PORT SERVICES!]"
    if $IPTABLES -X ; then
        $IPTABLES -P INPUT ACCEPT
        $IPTABLES -P FORWARD ACCEPT
        $IPTABLES -P OUTPUT ACCEPT
        log_action_end_msg $?
    else
        log_action_end_msg $?
    fi
    ;;

save)
    log_action_begin_msg "Saving current firewall configuration"
    if $IPTABLES_SAVE > $IPTABLES_CONFIG ; then
        log_action_end_msg $?
    else
        log_action_end_msg $?
    fi
    ;;

force-reload|restart)
    log_action_begin_msg "Reloading firewall configuration [Warning: POTENTIAL NETWORK INSECURITY DURING RELOAD]"
    $IPTABLES -F
    $IPTABLES -X
    if $IPTABLES_RESTORE < $IPTABLES_CONFIG ; then
        log_action_end_msg $?
    else
        log_action_end_msg $?
    fi
    ;;

*)
    echo "Usage: /etc/init.d/iptables {start|stop|save|restart|force-reload}"
    exit 1
    ;;
esac

exit 0

Your iptables rule is active once you execute it. Issuing a restart merely restores your iptables config to however it was last saved. There is no need to do the restart.

iptables-save
iptables-restore

will save rules in a plain text file and it will be restored on system startup by the init.d script. see iptables.conf e iptables man for details