Incompatible With Pf Program Version — Pf Configuration
modinfo pf | grep version
The error message occurs when the Packet Filter (PF) firewall configuration file syntax does not match the capabilities of the running PF kernel module or binary utility. This issue typically arises during operating system upgrades, custom kernel compilations, or when managing mixed-version environments in BSD-based systems (like FreeBSD, OpenBSD, or NetBSD) and macOS.
: Ensure the entire system is updated together. On FreeBSD, use freebsd-update to sync the kernel and userland [1]. Match Config Syntax FreeBSD 15.0
D) Custom/third-party kernel module mismatch
The error message "pf configuration incompatible with pf program version" is a common roadblock for system administrators and developers working with Packet Filter (PF) on BSD-based systems like FreeBSD, OpenBSD, or macOS. This error indicates a structural mismatch between the firewall rules you are trying to load and the version of the PF engine running in your system's kernel. pf configuration incompatible with pf program version
The error typically appears in three scenarios:
Upgrade the host kernel using freebsd-update or source compilation. Reboot the host system. Step 5: Clean Stale pfctl Binaries
Reboot your system if you recently updated the OS to ensure the active kernel matches the disk binaries.
This error typically appears when you try to load your Packet Filter (PF) rules using the pfctl command line tool. It indicates a fundamental breakdown in communication between the user space utilities and the kernel space firewall engine. modinfo pf | grep version The error message
If the pfctl binary utility is updated but the kernel module ( pf.ko ) fails to update, or if a custom kernel is loaded without updating userland tools, a binary-to-kernel version mismatch occurs. Step-by-Step Troubleshooting and Resolution
macOS transitioned through various versions of PF (Packet Filter), which was originally ported from OpenBSD. When users upgrade macOS, they often find that custom rules they wrote years ago use syntax (like certain NAT or ALTQ commands) that the newer "chef" has deprecated or removed.
→ Kernel is 6.9 (PF 1.9), pfctl is from 7.0 (incompatible). → Solution: Reboot into correct kernel, or reinstall matching userland.
is the one provided by the base system and not a leftover from a previous version. Summary of Impact Issue Type Primary Risk Recommended Action Partial Upgrade Firewall fails to load rules at boot. Run a full system update/repair. FreeBSD 15 Migration Syntax errors due to OpenBSD parity changes. release notes for syntax updates. Custom Kernel IOCTL version mismatch. Recompile userland world to match the kernel. Are you seeing this error during a pfSense upgrade or while working with a vanilla FreeBSD installation? On FreeBSD, use freebsd-update to sync the kernel
If you accidentally installed sysutils/pf or security/pf from ports, it may have placed a newer pfctl in /usr/local/sbin . To resolve:
If the chef (the program) gets upgraded to a newer version of "Packet Filter," they might no longer understand the shorthand or specific terms used in the old recipe book (the configuration).
PF evolves across OS versions. Common triggers: