CentOS Stream 10 – Common Problem 248 – Diagnosis and Fix

📖 ~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

TLS clients see Connection refused or OCSP response errors, harming Strict-Transport-Security clients.

Environment & Reproduction

Often related to network egress restrictions or insufficient SSLStaplingCache configuration.

Root Cause Analysis

Apache cannot reach the OCSP responder or the stapling cache is undersized for the certificate count.

Quick Triage

Inspect /var/log/httpd/error_log for OCSP and review SSLStapling directives in /etc/httpd/conf.d.

Step-by-Step Diagnosis

Run: sudo apachectl -M | grep -i ssl; grep -i ocsp /var/log/httpd/error_log; openssl s_client -status.

Solution – Primary Fix

Set SSLStaplingCache shmcb:/run/httpd/stapling(128000) and ensure outbound 80/443 to OCSP responder.

Solution – Alternative Approaches

Use a forward proxy or pre-fetch OCSP responses via cron and SSLStaplingForceURL to a trusted mirror.

Verification & Acceptance Criteria

openssl s_client -status returns a valid OCSP response and error_log shows no stapling warnings.

Rollback Plan

Disable SSLUseStapling temporarily and rely on client OCSP fetch while the issue is investigated.

Prevention & Hardening

Monitor stapling cache hit rate and OCSP responder health with synthetic checks.

Related Errors & Cross-Refs

Related to certificate chain order, CT log timing, and TLS session ticket rotation issues.

Related tutorial: View the step-by-step tutorial for centos-stream-10.

View all centos-stream-10 tutorials on the Tutorials Hub →

Browse all common problems & solutions on the Tutorials Hub.

References & Further Reading

mod_ssl documentation and Red Hat web server guide.