The manual page and help for the iptables-apply / ip6tables-apply Linux command. The iptables-apply command will try to apply a new rules file (as output from iptables-save, read by iptables-restore) or run a command to configure iptables and then ask the user if the changes are OK. If the new iptables rules break the existing connection, the user will not be able to respond in the affirmative. In this case, after the timeout, the script reverts to the previously working iptables rules.