Pf Configuration Incompatible With Pf Program Version Exclusive Info

When planning a major operating system upgrade, temporarily comment out complex, custom PF rules or fall back to a bare-minimum default rule set. Once the upgrade completes and the new kernel boots successfully, uncomment and update your advanced rules piece by piece.

Temporarily move your /etc/pf.conf to a backup and load the system's default config to see if the error clears.

which pfctl

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.

The error is a critical, yet common, issue encountered by system administrators managing BSD-based firewalls, most notably on OpenBSD , FreeBSD , and pfSense . pf configuration incompatible with pf program version

This version mismatch typically happens due to three common scenarios:

The error message 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.

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

Older PF versions treated packet normalization ( scrub ) as a distinct top-level action rule. Modern versions of PF have integrated scrubbing directly into standard filtering rules options. scrub in on ext_if all fragment reassemble Use code with caution. Modern Correct Syntax: match in all scrub (no-df random-id max-mss 1440) Use code with caution. 2. Missing or Altered state Keywords When planning a major operating system upgrade, temporarily

If you have multiple versions of pfctl installed (perhaps one in /sbin/ and another from a package in /usr/local/sbin/ ), ensure you are calling the one that matches your current kernel version. Diagnostic Command

This is the code running inside the operating system kernel that actually inspects packets, tracks state, and enforces the rules. It has its own internal data structures and API version.

: Attempting to load a configuration using syntax from a newer version (e.g., FreeBSD 15's integrated NAT) on an older kernel version. How to Fix It 1. Sync Your Kernel and Userland

During a major or minor OS upgrade (e.g., upgrading FreeBSD from 13.x to 14.x), the user-space utilities are often installed before the system reboots into the new kernel. If the boot process invokes pfctl while the old kernel is still active, the binary will look for new kernel structures that do not yet exist. 2. Mismatched Source Trees and Custom Kernels which pfctl The pf configuration incompatible with pf

If you run into trouble and need further help, the relevant mailing lists are excellent resources:

Once your kernel and user-space utilities match, test the configuration file parser without applying live changes to your firewall rules: pfctl -nf /etc/pf.conf Use code with caution.

Understanding and Fixing "pf configuration incompatible with pf program version"

typically occurs on macOS or BSD-based systems when there is a mismatch between the Packet Filter (pf) configuration file rules and the version of the utility or the system kernel.