I would like to tell my BSD based PF firewall to flush out the current configuration every 2 minutes. This will help me, when I’m testing a new rules and configuration options. [donotprint][/donotprint]Some time I find myself locked out of my own remote server. How do I reset PF firewall automatically without issuing hard reboot?
There is no need to write a shell script and call it from cron. You can load the rules from the /etc/pf.conf and sleep or 120 seconds then disable pf using the following syntax:
#/sbin/pfctl -f /etc/pf.conf && sleep 120 && /sbin/pfctl -d
- -f /etc/pf.conf – Load the rules contained in /etc/pf.conf.
- -d – Disable the packet filter.
- sleep 120: The sleep command suspends execution for a minimum of 200 seconds before calling the next command.
You can also test pf.conf for syntax errors using the following options:
# /sbin/pfctl -nf /etc/pf.conf
Finally, && (AND list) shell control operator is to used run next command only if, first command returns an exit status of zero. So each command in list must be successful in order to run next command.
# /sbin/pfctl -nf /etc/pf.conf && /sbin/pfctl -f /etc/pf.conf && sleep 120 && /sbin/pfctl -d
- How To Reset Linux Firewall Automatically While Testing Configuration With Remote Server Over SSH Session
- Man pages – ksh(1), and pfctl(8)