📖 ~1 min read
Table of contents
Symptom & Impact
`zypper refresh` aborts with TLS handshake failures, blocking patch installs across SLES 15 hosts.
Environment & Reproduction
Triggered after CA bundle rotation or NTP drift on registered SLES 15 SP servers.
Root Cause Analysis
Stale or missing intermediate CA certificates break TLS to SUSE Customer Center and RMT mirrors.
Quick Triage
Check `timedatectl` for clock skew and verify `/etc/ssl/ca-bundle.pem` is current.
Step-by-Step Diagnosis
Run `zypper –no-gpg-checks refresh -fdb` and inspect `/var/log/zypper.log` for failing hostnames.

Solution – Primary Fix
Reinstall `ca-certificates-mozilla`, run `update-ca-certificates`, then retry `zypper refresh`.
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Solution – Alternative Approaches
Temporarily redirect to a local RMT/SMT mirror with an internal CA that is already trusted.
Verification & Acceptance Criteria
`zypper refresh` succeeds and `SUSEConnect –status` shows all products active.
Rollback Plan
Restore prior `/etc/ssl` state with `snapper undochange` if certificate trust regresses.
Prevention & Hardening
Enable chronyd and track CA bundle versions through SUSE Manager or Salt.
Related Errors & Cross-Refs
Pairs with `SUSEConnect` HTTP 5xx and broken `zypper services` listings.
Related tutorial: View the step-by-step tutorial for sles-15.
View all sles-15 tutorials on the Tutorials Hub →
Browse all common problems & solutions on the Tutorials Hub.
References & Further Reading
SUSE doc TID about SCC TLS troubleshooting and ca-certificates package notes.
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