Ubuntu 22.04 LTS – SSH service is active but remote login is refused

📖 ~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

SSH clients receive connection refused, preventing remote administration.

Environment & Reproduction

Common after firewall policy changes or listening-address misconfiguration.

Root Cause Analysis

Port 22 is blocked by ufw/iptables or sshd listens only on localhost.

Quick Triage

Verify service state, listen socket, and host firewall rules.

Step-by-Step Diagnosis

Inspect logs while testing inbound SSH from another host.

Solution – Primary Fix

Allow SSH through firewall and bind sshd to server network interfaces.

Solution – Alternative Approaches

Use a custom SSH port and update firewall policy accordingly.

Verification & Acceptance Criteria

Remote SSH login succeeds and auth logs show successful sessions.

Rollback Plan

Restore previous sshd_config and firewall rules if access degrades.

Prevention & Hardening

Keep firewall-as-code and run config tests before sshd restarts.

Related Errors & Cross-Refs

Related issues include no route to host and permission denied errors.

Related tutorial: View the step-by-step tutorial for Ubuntu 22.04 LTS.

View all Ubuntu 22.04 LTS tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

Ubuntu 22.04 OpenSSH and UFW administration guides.