Affected versions: Debian 11

๐Ÿ“– ~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

Clients receive authentication failures and application database access stops.

Environment & Reproduction

Appears after host-based auth rules are reordered or tightened.

Root Cause Analysis

Rule mismatch in pg_hba.conf blocks expected user, host, or database access.

Quick Triage

Identify first matching pg_hba rule and verify connection parameters.

Step-by-Step Diagnosis

Review effective auth rules and corresponding PostgreSQL log entries.

Illustrative mockup for debian-11 โ€” terminal_or_shell
PostgreSQL connectivity and role checks โ€” Illustrative mockup โ€” Progressive Robot

Solution – Primary Fix

Correct pg_hba rules, reload config, and validate role authentication paths.

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Illustrative mockup for debian-11 โ€” log_or_config
pg_hba.conf and PostgreSQL log diagnostics โ€” Illustrative mockup โ€” Progressive Robot

Solution – Alternative Approaches

Apply temporary scoped trust on maintenance networks during recovery.

Verification & Acceptance Criteria

Required clients connect successfully with intended auth methods.

Rollback Plan

Revert pg_hba changes if new rules overblock production traffic.

Prevention & Hardening

Use tested auth templates and peer review for all pg_hba updates.

Related to DNS reverse lookup issues and TLS mode mismatches.

Related tutorial: View the step-by-step tutorial for debian-11.

View all debian-11 tutorials on the Tutorials Hub โ†’

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

PostgreSQL authentication and pg_hba management guidance.

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