Ipfw

ipfw is a kernel firewall. It is one of three firewall soultions delivered in the Release. The other two are userland applications, ipf (ipfilter) and pf (ported from openbsd). If you want to run ipfw, you need to create a firewall ruleset and the system will dynamically load the kernel module when the rc.conf statement firewall_enable="YES" is used. see also: Firewall, Configuring, Firewall, Monitoring