Adding a Leaf or Spine Device to an Existing Fabric Using ZTP
Starting with Contrail Networking release 1911, you can expand an existing greenfield fabric deployment by adding new leaf or spine devices. The feature is especially useful when you do not add all the required devices to the fabric on Day One and want to add devices to the fabric at a later point. You can add new devices to a fabric by uploading a YAML file that contains the device information.
To add a device to a fabric:
- Log into Contrail Command and navigate to Infrastructure > Fabrics > Fabric Name.
- Click Actions > ZTP Wizard.
The Create Fabric page is displayed.
- Click the browse link in the Device Info field and upload the YAML file that contains information about the
device, such as the serial number of the device, that you want to
add to the fabric.
Alternatively, you can drag and drop the .YAML or .yml in the Device Info field. You can add multiple new devices at a time. To add multiple devices, specify the serial numbers of the devices and the configuration details for each device in the YAML file as shown in the sample below.
Sample YAML File
supplemental_day_0_cfg: - name: 'cfg1' cfg: | set system ntp server 167.xx.20.98 device_to_ztp: - serial_number: '74035760356' supplemental_day_0_cfg: 'cfg1' hostname: 'test_device' device_functional_group: 'dfg1' loopback_ip: '10.xx.10.5' underlay_asn: '64015' mgmt_ip: '10.xx.13.42' to_ztp: false - serial_number: '55674325815' supplemental_day_0_cfg: 'cfg1' - serial_number: '11675330144' - serial_number: '74656088411'Table 1: Fields in the YAML file
Field
Description
serial_number
Specify the device serial number.
hostname
Enter a host name to identify the device. If a host name is not provided, the device serial number is used to identify the device.
device_functional_group
Enter a device functional group. A device functional group enables you to assign properties like OS version, and physical and routing-bridging roles to a user-defined group of devices instead of groups defined by node profiles. Using device functional groups enables configuring the devices in mixed-mode where devices in a single fabric can support different OS versions. Device functional groups are supported only for greenfield fabric onboarding.
loopback_ip
Enter an IP subnet to be assigned as loopback interface (lo0) addresses to fabric devices. The loopback interface IP addresses are required for iBGP peering in the overlay network. The field value must include a full CIDR with an IP address and a subnet mask.
underlay_asn
Enter the autonomous system number (ASN) that will be used to enable external BGP (eBGP) in the underlay network.
mgmt_ip
Enter the IP address to be assigned as management IP address for the devices.
Figure 1: Add a Device by Uploading a YAML File 
You can see that the fields Name, ASN Range, Fabric Subnet, Loopback Subnets, and PNF Servicechain Subnets are grayed out.
- Enter the root user password and click Next to proceed to the Device discovery page. Complete the steps in Discover a Device.
- Click Next to assign roles and complete the steps in Assign a Role to a Device.
- Click Autoconfigure.
- Navigate to Infrastructure > Fabrics > Fabric Name > Fabric Devices page and verify that the new devices are listed.
- Click Action > Reconfigure Roles to assign role to the new device.
To add devices successfully using this method, you must ensure that ASN numbers, Fabric Subnet IPs, and Loopback Subnet IPs are available for the number of devices to be added.