1. Log in to the CCN console and access the CCN management page.
2. Associate a network instance using either of:
   Option 1: associate the network instance on the details page.
   1. Click the ID/Name of the desired CCN instance to access the Associated Instances page. Click Add an instance.
   2. In the pop-up window, select a network instance type from VPC, Direct Connect Gateway, BM Virtual Private Cloud, and VPN Gateway. Select the region to which the network instance belongs and the specific network instance.

      Note：

      For CCN to automatically add the routes from the VPN gateway, the VPN gateway for CCN has the VPN tunnel created and SPD policy configured. For more information, see Connecting IDC to CCN.

   3. (Optional) To associate more network instances, click Add and follow the preceding steps.
   4. Click OK.
      
      Option 2: associate the network instance upon creation.
      When creating a CCN instance, add the network instances to be associated with it.
      

For more information on creating a network instance, refer to Creating VPCs and Creating Direct Connect Gateway.