Software firewall (APF / iptables) hackable?
Hi everybody, I'm wondering if anybody has a opinion or even experience if a software firewall like APF is 100% secure or if there is a way to let's say crash the process or change stuff from outside, so the firewall is not working properly anymore.A hardware firewall is pretty secure, cause there is no software that could be modified nor running processes that could be stopped without I would immediately notice this. The software scares me a little, cause if somebody can find a way to stop it let's say with a rootkit or so, then all ports are open again and everybody knows what's gonna happen then.
Or is there a solution to monitor the function of the APF like RKhunter does for several programs?
Any other recommendation to have a save and sound system other then RK-Hunter with daily report and APF with strict in an outbound port rules?