Pf Configuration Incompatible With Pf Program Version 【FAST ⇒】

If you just ran freebsd-update install or built a new world/kernel:

A: Yes, if you use the pf kernel module on Linux (e.g., via Gentoo or pfSense's underlying FreeBSD heritage). The same principle applies.

Depending on your operating system, specific syntax changes are notorious for causing this error. 1. The scrub Directive Changes

Run the following command:

For users who build OpenBSD from source, the "pf configuration incompatible" error is a classic pitfall. The official OpenBSD upgrade FAQ suggests a specific sequence: build and install a new kernel, then reboot, and then rebuild userland. If you reboot into a new kernel without first rebuilding the userland tools that go with it, you will trigger the mismatch. pf configuration incompatible with pf program version

If the error started occurring after a system upgrade, it means your userland utilities and kernel are out of sync. On FreeBSD

This guide explores the technical causes behind this mismatch and provides actionable steps to restore your firewall’s stability. What Causes This Error?

If the mismatch is caused by your package manager, try rebuilding the database to ensure matches your kernel version. pkg update -f

: Copying a pf.conf file from a newer OS version to an older machine. If you just ran freebsd-update install or built

→ Kernel is 6.9 (PF 1.9), pfctl is from 7.0 (incompatible). → Solution: Reboot into correct kernel, or reinstall matching userland.

The actual PF firewall code lives inside the operating system kernel. It inspects packets, manages state tables, and drops or passes traffic based on the rules active in the system memory.

This comprehensive guide explains why this error happens, how to diagnose the root cause, and the exact steps to fix it. Understanding the Root Cause

: Upgrading FreeBSD, OpenBSD, or macOS updates the PF engine, which may deprecate old syntax. If you reboot into a new kernel without

: You might be running an older version of pfctl located in a local directory (e.g., /usr/local/sbin ) instead of the system default version.

In rare cases, mismatched PF binaries persist due to System Integrity Protection. Boot into Recovery, disable SIP, remove conflicting PF tools, then re-enable SIP. This is a last resort.

To resolve this issue, your first move should be a system reboot. If you have recently performed a binary update (like freebsd-update ), the kernel needs to restart to initialize the new PF structures. If a reboot doesn't fix it, you should verify that your world and kernel are in sync. Running mismatched versions of the operating system's base components is the most frequent culprit. For those managing custom builds, ensuring that the SRC_BASE matches the running kernel is vital.