In the first part of this blog series, we created the Linux VM in Oracle Cloud VMware Solution. In the second part of this blog series, we created the two autonomous databases to use for a private connection with the Linux VM from the first blog. In the last part of the blog, we created two Oracle Cloud Infrastructure (OCI) Autonomous Database services databases, one with access through a private endpoint within a VCN and another using access through a service gateway. We installed the Oracle client on the Oracle Cloud VMware Solution virtual machine (VM).

In part 3 of this blog, we configure the DNS and network connectivity for the Oracle Cloud VMware Solution VM to access the autonomous database and test the connectivity.

Step 1: Configure the DNS resolver on NSX to resolve the database DNS name from Oracle Cloud VMware Solution VM

This article is based on the document, Configuring DNS Forwarding in NSX-T.

Connect to the NSX Manager from the JumpHost. To get the NSX Manager URL, username and password go to the Oracle Cloud VMware Solution SDDC page:

A screenshot of the OCVS-Demo details page in the Oracle Cloud Console with the NSX initial username and password outlined in red.

Then log in to the NSX URL.

A screenshot of the VMware NSX-T login page.

Select Networking, DNS (under IP Management), and DNS Zones. We create a DNS server with the IP address SDDC NSX Edge Uplink 1 VLAN and add one for the DNS Servers. To find out the IP address of the SDDC NSX Edge Uplink 1, go to the software-defined data center (SDDC) Networks section under Resources.

A screenshot of the SDDC Networks page on the VLANs tab with the VLAN gateway CIDR outlined in red.

Back at the NSX manager, add a DNS zone with the IP address of the SDDC NSX Edge Uplink 1 and add 1 to the last octet.

A screenshot of the DNS Services page in VMware NSX-T with the DNS zones tab, Add DNS Zone button, and the zone name outlined in red.

Add a DNS service by clicking the DNS Services section and then Add DNS Service. You can use any private IP address that doesn’t conflict with the Oracle Cloud VMware Solution SDDC virtual cloud network (VCN) or SDDC workload network. In this case, I picked 192.168.50.1.

Then go to Networking, and under Tier-1 Gateways ensure that all DNS forwarder routes are enabled.

A screenshot of the Tier-1 Gateways page with assorted sections outlined in red.

Then go to Networking, Tier-0 Gateways, and click the three dots. Then click Edit.

A screenshot of the Tier-0 Gateways page with various sections outlined in red.

Click the 1 next to “Route Redistribution.”

A screenshot of the Set Route Re-distribution page with the 1 outlined in red.

Click Add Route Redistribution.

A screenshot of the Set Route Re-distribution page with the blue Add route re-distribution button outlined in red.

Update the route redistribution according to the following screenshot:

A screenshot of the Route Re-distribution page with the tier-0 subnets selected as static routes and DNS forwarder IP and the advertised tier-1 subnets' connected interfaces and segments as service interface subnet and connected segment.

Step 2: Configure network connectivity and test access to Oracle Autonomous Database from Oracle Linux VM

To enable the Oracle Cloud VMware Solution VM access to Autonomous Database through the service gateway, click Configure connectivity to Oracle Service Network on the Oracle Cloud VMware Solution cluster page.

A screenshot of the OCVS-Demo details page with the Configure connectivity to Oracle Services Network tab outlined in red.

Enter the SDDC workload CIDR from the Oracle Cloud VMware Solution page and click Next.

A screenshot of the Configure Connectivity to Oracle Services Network window with the SDDC Workload CIDR outlined in red.

Review the connectivity information and click Apply Configuration.

A screenshot of the Configure Connectivity to Oracle Services Network page on the Review and Apply Configuration tab with details filled in adn the Apply Configuration button outlined in red.

On the target VM, unzip the two wallet ZIP files and extract the value for host from the tnsnames.ora to test connectivity to the host using the following commands.

% nc -tv j0qqm02.adb.ap-tokyo-1.oraclecloud.com 1522 # database connectivity by VCN

% nc -tv adb.ap-tokyo-1.oraclecloud.com 1522 # database connectivity by service gateway

The connectivity to the database through the VCN isn’t working. However, connectivity to the database with connectivity setup through the service gateway is working.

A screenshot of the code example in Cloud Shell.

If the DNS resolution for the host name isn’t resolving, check that the file on the virtual machine /etc/resolv.conf has the following entry for the DNS Service IP (in this case 192.168.50.1). You might need to reboot the VM. If the entry isn’t there, you might need to add it manually and then check that the hostname resolves using the previous commands.

% cat /etc/resolv.conf
# Generated by NetworkManager
nameserver 192.168.50.1

Go to the VM and open SQL Developer. Click the + sign, as shown within the Oracle SQL Developer application.

A screenshot of the Oracle SQL Developer dashboard with the plus sign outlined in red.

Enter the new database connection details.

A screenshot of the New/Select Database Connection with the inputted name, username, password, and configuration detilas outlined in red.

Enter the database name, admin username, and password. Choose cloud wallet for the connection type and click Browse to choose the wallet file. In this case, we use the autonomous database configured with access using the service gateway wallet.

A screenshot of a browser window with the wallet zip file highlighted.

Ensure that the connectivity to the database configured with connectivity through the service gateway is working.

A screenshot of SQL Developer with the service gateway outlined in red.

To fix the connectivity for the database “js-ocvsvcn-adb,” go to the database page and click the subnet. In this example, we use Subnet-Oracle Cloud VMware Solution-Demo.

A screenshot of the Autonomous Database Details page for the example connection with the subnet outlined in red.

On the subnet page, click the route table. Our example uses “Route Table for Subnet-Oracle Cloud VMware Solution-Demo.”

A screenshot of the Subnet Details page with the Route Table outlined in red.

On the route table, add a route for the SDDC Workload CIDR block that points to NSX Edge.

A screenshot of the Route Table Details page with the route rules outlined in red.

To view the SDDC workload CIDR, go to the Oracle Cloud VMware Solution cluster page.

A screenshot of the OCVS-Demo details page in the Console with the SDDC Workload CIDR outlined in red.

This time, connectivity to the database endpoint works. The IP address is the private endpoint IP address of the database.

% nc -tv 10.12.0.122 1522

A screenshot of the code output with the IP addressed outlined in red.

Back to the VM, in Oracle SQL Developer, click the + sign to add a connection. Enter the autonomous database configured with private endpoint wallet details.

A screenshot of the New / Select Database Connection with the name, username, password, and configuration details outlined in red.

A new query builder session is created. Enter the following query:

Select * from v$database

Click the green arrow button to get the following output:

A screenshot of the resulting output in SQL Developer.

This example demonstrates a successful connection from the OCI Oracle Cloud VMware Solution virtual machine to Oracle Autonomous Database using a VCN private endpoint and Oracle Autonomous Database using a service gateway.

Want to learn more?

For more information about Oracle Cloud VMware Solution and Autonomous, see the following resources: