You are troubleshooting an issue where a compute instance in a private subnet within a VCN cannot reach OCI Object Storage. You have verified that a…

Problem: Instance in private subnet can’t reach Object Storage despite Service Gateway and routing.

Option A: Service Gateway enables private access; public IP isn’t required—incorrect.

Option B: Security lists/NSGs act as firewalls; if outbound traffic to Object Storage CIDR isn’t allowed,

connectivity fails—most likely and correct.

Option C: Service Gateway defaults to all OCI services unless restricted; less likely given setup

verification—incorrect.

Option D: Oracle Cloud Agent is for management, not connectivity—incorrect.

Conclusion: Option B is the most probable cause.

Oracle states:

"For private access to Object Storage via a Service Gateway, ensure security lists or NSGs allow

outbound traffic to the Object Storage CIDR block."

This supports Option B. Reference: Service Gateway Troubleshooting - Oracle Help Center

(docs.oracle.com/en-us/iaas/Content/Network/Tasks/servicegateway.htm#troubleshooting).