Automating Cisco IOS-XE Interface Configuration with Ansible Loops

In this blog, I'll show how to use Ansible to automate interface configuration across multiple Cisco IOS-XE routers using a loop. This is especially useful for bulk interface provisioning and ensuring consistency across your edge routers.

Objective

Configure 2 WAN Edge routers (IOS-XE) with multiple interfaces (WAN + OSPF) using a single playbook, leveraging:

• Grouped hosts in inventory

• Per-host variables stored in host_vars

• Ansible loop to iterate through interfaces

Topology

Project Layout

ansible/

├── cisco-config.yml # Main playbook

├── inventory/

│ └── hosts # Inventory file listing the IOS-XE devices

├── host_vars/

│ ├── 10.1.1.181.yml # Host-specific variables for router 10.1.1.181

│ └── 10.1.1.184.yml # Host-specific variables for router 10.1.1.184

Inventory Structure

We maintain a structured inventory and variable layout:

# inventory/hosts
[ios-xe]
10.1.1.181
10.1.1.184

Per-host variables:

📁 host_vars/10.1.1.181.yml

interfaces:
  - { wan_interface: "GigabitEthernet1", wan_description: "WAN1", wan_ip: "192.168.1.1", wan_mask: "255.255.255.0" }
  - { wan_interface: "GigabitEthernet2", wan_description: "OSPF-INTERFACE", wan_ip: "192.168.20.1", wan_mask: "255.255.255.0" }

📁 host_vars/10.1.1.184.yml

interfaces:
  - { wan_interface: "GigabitEthernet1", wan_description: "WAN1", wan_ip: "192.168.2.1", wan_mask: "255.255.255.0" }
  - { wan_interface: "GigabitEthernet2", wan_description: "OSPF-INTERFACE", wan_ip: "192.168.20.2", wan_mask: "255.255.255.0" }

The Ansible Playbook

cisco-config.yml:

---
- name: Configure 2 WAN Edges connected and OSPF
  hosts: ios-xe
  gather_facts: no
  connection: network_cli

  tasks:
    - name: Interface Configurations
      cisco.ios.ios_config:
        lines:
          - description {{ item.wan_description }}
          - no shutdown
          - ip address {{ item.wan_ip }} {{ item.wan_mask }}
        parents: interface {{ item.wan_interface }}
      loop: "{{ interfaces }}"

---

Run the Playbook

#ansible-playbook -i inventory/hosts cisco-config.yml

---

Output Highlights

PLAY RECAP *********************************************************************

10.1.1.181 : ok=1 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

10.1.1.184 : ok=1 changed=1 unreachable=0 failed=0 skipped=0 rescued=0 ignored=0

Each router receives the interface configuration defined in its own host_vars YAML file.

Running configuration of 10.1.1.181

interface GigabitEthernet1
 description WAN1
 ip address 192.168.1.1 255.255.255.0
 negotiation auto
!
interface GigabitEthernet2
 description OSPF-INTERFACE
 ip address 192.168.20.1 255.255.255.0
 negotiation auto
!

Running configuration of 10.1.1.184

interface GigabitEthernet1
 description WAN1
 ip address 192.168.1.1 255.255.255.0
 negotiation auto
!
interface GigabitEthernet2
 description OSPF-INTERFACE
 ip address 192.168.20.1 255.255.255.0
 negotiation auto
!

This is achieved through a loop, ensuring scalability and flexibility when configuring multiple routers or interfaces.

Tips

• Use network_cli for Cisco IOS devices, and ensure SSH + privilege access is enabled.

• Store variables per device in host_vars/ for modularity.

• Validate results with show running-config or collect configs using ios_command.

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Feel free to clone, adapt, and expand this example to suit your network automation workflows. Automation doesn't have to be complex — start small, and grow from there!