Pf Configuration Incompatible — With Pf Program Version __top__

Running a pf.conf file designed for OpenBSD on a FreeBSD system—or vice versa—frequently triggers this error. While they share a lineage, their PF implementations have branched significantly over the years.

The pf configuration incompatible with pf program version error is rarely a broken config file; it is usually a cry for help from an out-of-sync system. Aligning your userland utilities with your running kernel version via a clean reboot or system update will resolve the conflict in most scenarios.

which pfctl

or "syntax error" : Points to an obsolete keyword.

Modern firewall distributions have built-in mechanisms to "detangle" configurations. pf configuration incompatible with pf program version

uname -a freebsd-version -k # (For FreeBSD users) freebsd-version -u # (For FreeBSD users) Use code with caution.

freebsd-version -kru | uniq

This message typically appears when running pfctl (the Packet Filter control program) to load or validate a firewall ruleset. It signals a critical mismatch between the userland utilities (the compiler and control tools) and the in-kernel Packet Filter module. In simpler terms, the tool you are using to talk to the firewall speaks a different language than the firewall kernel module listening for instructions.

This error tells you that the version of the kernel module (the "program version") and the user-land tools (the "configuration") are no longer speaking the same language, making communication impossible. This is a hard failure designed to prevent system instability or crashes that could arise from an incompatible setup. Running a pf

calls may fail if they were compiled against a library version different from the one currently installed. Netgate Forum 253479 – [pf] pfctl: DIOCADDRULE: Invalid argument