---
title: "Set vNIOS Instance as Primary DNS for Subnet"
canonical: "https://docs.infoblox.com/space/DeploymentGuidevNIOSforOCI/1557364833/Set%20vNIOS%20Instance%20as%20Primary%20DNS%20for%20Subnet"
format: markdown
---
OCI allows you to specify custom DNS name servers for your VCN using DHCP options. These can be name servers on the Internet, in a VCN, or in your on-premises network via VPN or FastConnect. Prior to setting your vNIOS for OCI instance as a name server for your VCN, ensure you have configured the DNS service. Refer to [https://docs.infoblox.com](https://docs.infoblox.com) for details on configuring the DNS service.

1. In the OCI console, use the services menu to navigate to **Networking** **→ Virtual Cloud Networks**.

2. Click on your VCN.

3. On the VCN Details page, click on **DHCP Options** under Resources.

4. Click on **Create DHCP Options**.

![image-20250526-101321.png](media://a9b03c58-5d90-459b-974d-ec89dc4f513e)

5. In the Create DHCP Options window, enter a name.

6. For DNS Type, select **Custom Resolver**.

7. For DNS Server, enter the private IP address of your vNIOS for OCI instance LAN1 VNIC.

8. Click on **Create DHCP Options**.

![image-20250526-101347.png](media://960f243c-9dfa-4399-9bc3-540fb51e23c8)

![image-20250526-101401.png](media://7b6329cf-0ee1-437f-87c6-a3a531246c51)

9. To set your newly created DHCP Options for a subnet, click on **Subnets** under Resources.

10.  Click on the Subnet you want to edit.

![image-20250526-101434.png](media://7fc8f4f7-288f-4bf7-a36d-d3a98c16f288)

11.  On the Subnet Details page, click **Edit**.

![image-20250526-101450.png](media://ee26fae1-6ec0-4ec5-ab18-3ad2aa6e1e85)


12.  On the Edit Subnet pane, use the DHCP Options dropdown to select your new DHCP Option.

13.  Click on **Save Changes**.

![image-20250526-101506.png](media://f57e2d42-11d5-48c8-92b5-de8e633a5fdc)

14.  You can now see the new DHCP Options set on the Subnet Details page.

![image-20250526-101524.png](media://5c30781c-83b4-4ddf-94b4-84dedf252bca)


15.  You will need to reboot or restart the DHCP client of any existing instances on the subnet for the change to take effect.