FreeBSD 13 – pf rule set unintentionally blocks SSH management access

📖 ~1 min read

Table of contents

1. Symptom & Impact
2. Environment & Reproduction
3. Root Cause Analysis
4. Quick Triage
5. Step-by-Step Diagnosis
6. Solution – Primary Fix
7. Solution – Alternative Approaches
8. Verification & Acceptance Criteria
9. Rollback Plan
10. Prevention & Hardening
11. Related Errors & Cross-Refs
12. References & Further Reading

Symptom & Impact

Remote SSH administration is blocked after a pf ruleset reload.

Environment & Reproduction

Triggered by rule reorder, macro edits, or table updates.

Root Cause Analysis

A broad deny or quick rule precedes management allow rules.

Quick Triage

Confirm sshd health first, then inspect effective pf policy.

Step-by-Step Diagnosis

Use pf counters and packet capture to identify the blocking rule.

Solution – Primary Fix

Insert explicit management pass rule early and validate before reload.

Solution – Alternative Approaches

Apply temporary emergency anchor allowlist during incident response.

Verification & Acceptance Criteria

SSH from approved management sources succeeds consistently.

Rollback Plan

Reload the last known-good pf.conf backup.

Prevention & Hardening

Require pf syntax checks and peer review for every firewall change.

Related Errors & Cross-Refs

Related to NAT order errors and stale pf state tables.

Related tutorial: View the step-by-step tutorial for FreeBSD 13.

View all FreeBSD 13 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

pf.conf manual and FreeBSD firewall operations guidance.