pfctl -f /etc/pf.conf
Before you panic, identify the exact symptoms:
The error “pf configuration incompatible with pf program version” is a clear symptom of version drift between the PF userland tool and the in-kernel PF module. While alarming at first glance, the diagnosis is straightforward: check the versions of pfctl and the kernel PF module, identify the older component, and bring them into alignment—usually by rebooting after a system update or correcting the module load path.
Check your PF version’s man page:
Navigate to the pfctl source directory (usually /usr/src/sbin/pfctl ). Run make clean && make && make install .
On OpenBSD, PF is integrated into the base system and kernel. Mismatch is extremely rare unless you mix -current and -release binaries. Fix: Reinstall matching userland and kernel from the same snapshot or release.
# Default block policy set block-policy drop # Skip filtering on the loopback interface set skip on lo0 # Default deny all incoming, allow all outgoing block in all pass out all keep state Use code with caution. Test and load this basic ruleset: sudo pfctl -nf /etc/pf.conf sudo pfctl -f /etc/pf.conf Use code with caution. pf configuration incompatible with pf program version
Example output:
net.pf.version: 1.8.0
pfctl -V
Yes, macOS uses PF as its firewall. If you upgrade macOS without ensuring compatibility, you may encounter similar issues. The pfctl command on macOS works in much the same way, though the kernel module may have Apple-specific modifications.
Use absolute paths ( /sbin/pfctl ) to rule out an environment path issue.
: After the update, use freebsd-update IDS to list any files with hash mismatches. If /sbin/pfctl or other PF-related files are listed as mismatched, the update is incomplete. pfctl -f /etc/pf
ls -l /sbin/pfctl
: Never reboot after a kernel upgrade without completing the userland rebuild. On OpenBSD, this means completing the entire make build and make install process before rebooting.