Troubleshooting DNS resolution issues in OpenShift v4 internal networking 1. Understand the DNS Resolution Flow in OpenShift 2. Initial Checks and Information Gathering 3. Verify Pod-Level DNS Configuration 4. Inspect the dns-default Service and Endpoints 5. Examine CoreDNS Configuration and Logs in Detail 6. Check Network Policies 7. Verify Node-Level DNS and Connectivity 8. Upstream DNS Server Issues (for External Resolution)