OCI Networking guide: how to to Reach Private Subnet from Public Subnet despite Security Rules
After trying multiple solutions online, I still can't figure this out. I'm experiencing a challenging scenario with my OCI networking setup. I have a public subnet where my web servers are hosted and a private subnet containing my database servers. The architecture is supposed to allow communication from the public subnet to the private subnet for API calls. However, I keep receiving a 'Network unreachable' behavior when trying to connect to the database from the application running in the public subnet. I've already checked the following configurations: - The security lists for the private subnet have an ingress rule allowing traffic from the public subnet CIDR. - The route table for the private subnet has a rule pointing back to the internet gateway for outbound traffic. Here are some snippets of the configurations I have: **Security List for Private Subnet**: ```json { "ingressRules": [ { "protocol": "6", "source": "10.0.0.0/24", "tcpOptions": { "destinationPortRange": { "min": "1521", "max": "1521" } } } ] } ``` **Route Table for Private Subnet**: ```json { "routes": [ { "destination": "0.0.0.0/0", "target": "internetGatewayId" } ] } ``` Also, I performed a telnet test from the public subnet to the database IP and it fails: ```bash telnet 10.0.1.10 1521 ``` This gives me a timeout, which is really puzzling, as I can successfully ping the private subnet from the public one. I've verified that the database listener is up and running and that there are no issues on that end. The OCI instance's VNICs are correctly configured as well. Could there be something Iām overlooking, like a missing NAT gateway or a firewall scenario? Any insights or troubleshooting steps would be greatly appreciated! This is part of a larger application I'm building. Any help would be greatly appreciated!