// Module included in the following assemblies:
//
// * networking/multiple_networks/creating-primary-nad.adoc

:_mod-docs-content-type: REFERENCE
[id="approaches-managing-additional-network_{context}"]
= Approaches to managing a primary network

[role="_abstract"]
You can manage the life cycle of a primary network created by a NAD CR through the Cluster Network Operator (CNO) or a YAML manifest. Using the CNO provides automated management of the network resource, while applying a YAML manifest allows for direct control over the network configuration.

Modifying the Cluster Network Operator (CNO) configuration:: With this method, the CNO automatically creates and manages the `NetworkAttachmentDefinition` object. In addition to managing the object lifecycle, the CNO ensures that a DHCP is available for a primary network that uses a DHCP assigned IP address.

Applying a YAML manifest:: With this method, you can manage the primary network directly by creating an `NetworkAttachmentDefinition` object. This approach allows for the invocation of multiple CNI plugins in order to attach primary network interfaces in a pod.

Each approach is mutually exclusive and you can only use one approach for managing a primary network at a time. For either approach, the primary network is managed by a Container Network Interface (CNI) plugin that you configure.

[NOTE]
====
When deploying {product-title} nodes with multiple network interfaces on {rh-openstack-first} with OVN SDN, DNS configuration of the secondary interface might take precedence over the DNS configuration of the primary interface. In this case, remove the DNS nameservers for the subnet ID that is attached to the secondary interface by running the following command:

[source,terminal]
----
$ openstack subnet set --dns-nameserver 0.0.0.0 <subnet_id>
----
====