Pf Program Version - Pf Configuration Incompatible With

The error message "pf configuration incompatible with pf program version" typically occurs in UNIX-like operating systems (such as FreeBSD or OpenBSD) and networking appliances like pfSense. It signals a mismatch between the kernel-level Packet Filter (PF) engine and the userland utility (pfctl) used to manage it.

Key scenarios to detect

  1. Newer config uses features not present in older pf binary (e.g., syntax added in later OpenBSD/FreeBSD/NetBSD pf releases).
  2. Older-style/deprecated constructs removed in newer pf binaries.
  3. Version-specific macro/option differences (e.g., table modifiers, route-to semantics, anchor behavior).
  4. Mixed include files targeting different pf versions.
  5. Binary reports load failure with generic error; feature extracts root cause.

Version Mismatch: You are using a version of the pfctl binary that is newer or older than the pf kernel module. This often happens after a partial system upgrade where the userland tools were updated but the system wasn't rebooted to load the new kernel. pf configuration incompatible with pf program version

Partial OS Updates: A system update was interrupted, or only the kernel was updated without updating the rest of the base system. The error message "pf configuration incompatible with pf

The "pf configuration incompatible with pf program version" error can have significant implications on network security and functionality: Newer config uses features not present in older pf binary (e

OS

sysctl kern.version OpenBSD 6.9 (GENERIC) #1

Roadmap / Phases

  1. MVP: parser + version map for common constructs on OpenBSD and FreeBSD; CLI check and human-readable output.
  2. Add automated safe fixes, JSON output, and systemd/init hooks.
  3. Integrate with GUIs and package manager hooks; expand to other BSDs and forks.
  4. Maintain community-updatable version database.
  • Edit /etc/pf.conf and remove or change that directive to a syntax supported by your OS version (see man pf.conf).
  • Re-run pfctl -nf and then reload.

. This is most common in FreeBSD-based environments (like pfSense or OPNsense) following a partial update or a custom kernel build. Key Causes & Context Kernel vs. Userland Mismatch firewall is implemented in the kernel, but the