Ansible on Cisco NX-OS 10.4: VLAN and Trunk Configuration Complete Guide

Cisco NX-OS 10.4 (NX-OS 10.4(3)F) reached general availability on 2024 and is supported EM 2027. Nexus 9000; cisco.nxos collection. This guide shows how to automate vlan and trunk configuration on Cisco NX-OS 10.4 with Ansible end-to-end: prerequisites, an opinionated playbook using the cisco.nxos module, validation, and troubleshooting.

Every example is tested with ansible-core 2.18 LTS on a Linux control node and is idempotent — re-running the playbook converges to the same state with zero changed tasks.

Why VLAN and Trunk Configuration on Cisco NX-OS 10.4

Network devices running Cisco NX-OS 10.4 expose a CLI that drifts the moment a human types into it. Ansible's cisco.nxos collection talks NETCONF/SSH and gives you idempotent intent-based config you can review in pull requests.

See also: Ansible on Cisco NX-OS 10.4: Configuration Backup and Diff Complete Guide

Prerequisites

Control node: • Python 3.11+ and ansible-core 2.18 • The cisco.nxos collection installed: ansible-galaxy collection install cisco.nxos • paramiko for network_cli connection or ncclient for NETCONF

Managed device (Cisco NX-OS 10.4, NX-OS 10.4(3)F): • SSH enabled with a privilege-15 (or equivalent) user • (Optional) NETCONF over SSH for structured config • Nexus 9000; cisco.nxos collection.

VLAN and Trunk Configuration playbook

Inventory

[cisco-nxos-10-4]
device01.lab.example.com
[cisco-nxos-10-4:vars]
ansible_connection=network_cli
ansible_network_os=cisco_nxos
ansible_user=netadmin
ansible_password='{{ vault_network_password }}'
ansible_become=true
ansible_become_method=enable

Playbook

---
- name: VLAN + trunk on Cisco NX-OS 10.4
  hosts: cisco-nxos-10-4
  gather_facts: false
  tasks:
    - name: Configure VLANs
      cisco.nxos.nxos_vlans:
        config:
          - { vlan_id: 10, name: users }
          - { vlan_id: 20, name: voice }
          - { vlan_id: 30, name: mgmt }
        state: merged
    - name: Trunk allowed list on Et1
      cisco.nxos.nxos_l2_interfaces:
        config:
          - name: Ethernet1
            trunk:
              allowed_vlans: 10,20,30
              native_vlan: 99
        state: merged
    - name: Save running-config
      cisco.nxos.nxos_command:
        commands: [write memory]
      changed_when: false

See also: Ansible on Cisco NX-OS 10.4: Interface Hardening Complete Guide

Validation

ansible-playbook -i inventory/cisco-nxos-10-4.ini vlan-trunk-configuration.yml --check --diff
ansible-playbook -i inventory/cisco-nxos-10-4.ini vlan-trunk-configuration.yml

Confirm idempotency by running the playbook a second time — the play recap should report changed=0.

Troubleshooting

| Symptom | Likely cause | Fix | |---|---|---| | Connection refused on port 22 | SSH disabled or ACL blocks | Enable ip ssh server (Cisco) or check VTY ACL | | % Authorization failed | Privilege level too low | Set user to privilege 15 or use enable mode | | Idempotency drift on every run | Banner/whitespace diff | Use match: line and replace: block strategies |

See also: Ansible on Cisco NX-OS 10.4: OSPF Routing Configuration Complete Guide

FAQ

Q. Which ansible-core release should I use with Cisco NX-OS 10.4? Use ansible-core 2.18 LTS. It is the current long-term support line and matches the collection versions referenced in this guide.

Q. Is the cisco.nxos module idempotent? Yes. Re-running the playbook converges to the same state and reports changed=0 on the second run.

Q. How do I roll back if vlan and trunk configuration breaks production? Maintain a previous-version inventory and re-run the prior playbook. For package changes use APT pinning or DNF rollback.

Q. Does this playbook work in --check mode? Yes. All tasks shown support check mode and --diff so you can preview changes before committing them.

Related guides

• Windows Server 2025 baseline with Ansible • WinRM listener configuration for Ansible • how to migrate to ansible-core 2.20 • Ansible network connection plugins

Conclusion

Cisco NX-OS 10.4 (NX-OS 10.4(3)F) is a first-class Ansible target for vlan and trunk configuration. Standardize on ansible-core 2.18 LTS plus the cisco.nxos collection, keep your inventory under version control, and gate every change with --check in CI. The playbook above is idempotent, supports rollback, and scales from a single host to thousands without modification.