After setting up the IDE and Python environment, the next step is to configure the VXLAN Data Model using Network as Code. This data model streamlines VXLAN fabric configuration by abstracting automation processes and representing the desired fabric state. Operators can simply update the configuration state within the data model, eliminating the need to develop custom playbooks with individual modules and parameters.

Utilizing straightforward YAML, the VXLAN as Code VXLAN EVPN collection enables the definition of data structures that describe the VXLAN fabric configuration for Cisco Nexus data centers. This configuration can then be deployed using Ansible and Cisco Nexus Dashboard. Even with minimal automation experience, operators can leverage this collection to instantiate a VXLAN EVPN fabric efficiently.

Step 1 - Installing the Example Repository

For your convenience, a GitHub repository containing all the required files to build the VXLAN fabric has been provided. The initial step is to clone the repository.

git clone https://github.com/cobedien/nac-ltrdcn-2654.git

Step 2 - Move to the new Directory

cd nac-ltrdcn-2654

Step 3 - Install Ansible and Additional Tools

pip install --upgrade pip
pip install -r requirements.txt

Step 4 - Install Ansible Galaxy Collection

ansible-galaxy collection install -r requirements.yaml

Step 5 - Set POD05 Environment Variables

Environment variables are configured in the shell that will execute the playbook, using the export command in Bash. This is where you will define your local variables.

# These are the credentials for ND
export ND_HOST=10.3.0.23
export ND_DOMAIN=cl-ise
export ND_USERNAME=pod5u1
export ND_PASSWORD=cisco.123
# These are the credentials for the devices in the inventory
export NDFC_SW_USERNAME=admin
export NDFC_SW_PASSWORD=cisco.123

Step 6 - Configuring Local Variables

After cloning the base repository, you'll need to modify specific variables to adapt it to your particular POD. This example demonstrates the ease of using Network as Code (NaC) to automate Nexus Dashboard tasks..

In this particular example, the idea is to highlight how easy is to use Network As Code to automate Nexus Dashboard tasks. We will be modifying a port 1/10 on Site1-L1 from switchport mode trunk to switchport access vlan 2301

To streamline this process, use the sed command to insert the appropriate POD information into the topology.nac.yaml file.

Modify the Default Gateway from Site1-L1

sed -i 's/<< DG >>/10.3.5.1/' host_vars/Site1/topology.nac.yaml

Modify the Manegement IP address from Site1-L1

sed -i 's/<< MGMT >>/10.3.5.13/' host_vars/Site1/topology.nac.yaml

Step 7 - Login to Site1-L1

Login to your Site1-L1 switch using the copy command below and paste into your Terminal. When prompted, the password is cisco.123 .

Step 8 - Site1-L1: Show Run Interfaces Ethernet 1/10

show run interface ethernet 1/10

Output:

Site1-L1# show run interface ethernet 1/10

!Command: show running-config interface Ethernet1/10
!Running configuration last done at: Wed Jun  4 15:49:34 2025
!Time: Wed Jun  4 16:50:56 2025

version 10.5(3) Bios:version  

interface Ethernet1/10
  switchport mode trunk
  switchport trunk allowed vlan none
  spanning-tree port type edge trunk
  mtu 9216

Step 9 - Execute VXLAN as Code

With the environment variables configured, the final step is to execute the playbook to provision Nexus Dashbboard with the new port configuration.

Please note that this playbook may require additional time to complete, as Network as Code will generate all necessary files for the environment in the background.

ansible-playbook -i inventory.yaml vxlan.yaml --tags cr_manage_interfaces,role_deploy

Here is the output that you should see after the playbook has completed.

TASK [cisco.nac_dc_vxlan.deploy : Mark Stage Role Deploy Completed] ***************************************************
ok: [Site1 -> localhost]

PLAY RECAP ************************************************************************************************************
Site1                      : ok=189  changed=25   unreachable=0    failed=0    skipped=439  rescued=0    ignored=0   

Step 10 - Site1-L1: Check Configuration

show run interface ethernet 1/10

Output:

Site1-L1# show run interface ethernet 1/10

!Command: show running-config interface Ethernet1/10
!Running configuration last done at: Wed Jun  4 16:52:01 2025
!Time: Wed Jun  4 16:52:34 2025

version 10.5(3) Bios:version  

interface Ethernet1/10
  description BlueNet1 Vlan 2301 Site1-L1 1/10
  switchport access vlan 2301
  spanning-tree bpduguard disable

As you can see the configuration has been updated to access proctors.

By utilizing Network As Code, users can automate various tasks, including the creation of VRFs, VNIs, policies, and more. This lab guide employs Network As Code to configure the entire lab environment. For additional details, please consult one of the proctors.

Please continue to the next section.