https://oscarchou.com/tags/cloud-security/ Recent content in Cloud Security on Oscar's Notebook Hugo -- gohugo.io en-US Fri, 03 Apr 2026 20:00:00 +1300 https://oscarchou.com/posts/howto/oci-open-port/ Fri, 03 Apr 2026 20:00:00 +1300 https://oscarchou.com/posts/howto/oci-open-port/ Connection failures on Oracle Cloud Infrastructure (OCI) are rarely code errors—they are networking issues. This guide provides an ultimate, step-by-step checklist for debugging connectivity, detailing the four crucial layers: OCI Network Firewall (NSG/Security List), VCN subnet boundary, OS firewall (iptables), and application binding. Learn the systematic approach to ensure reliable service exposure.