How to do it...

1. Inside the ch2_ios directory, create the groups_vars folder.
2. Inside the group_vars folder, create the network.yml file with the following content:

$cat network.yml
Ansible_network_os: ios
Ansible_connection: network_cli
Ansible_user: lab
Ansible_password: lab123
Ansible_become: yes
Ansible_become_password: admin123
Ansible_become_method: enable

3. On all IOS devices, ensure that the following is configured to set up SSH access:

!
 hostname <device_hostname>
 !
 ip domain name <domain_name>
 !
 username lab secret 5 <password_for_lab_user>.
 !
 enable secret 5 <enable_password>.
 !
 line vty 0 4
 login local
 transport input SSH
 !

4. Generate SSH keys on the Cisco IOS devices from the config mode, as shown in the following code snippet:

(config)#crypto key generate rsa
 Choose the size of the key modulus in the range of 360 to 4096 for your
 General Purpose Keys. Choosing a key modulus greater than 512 may take
 a few minutes.
How many bits in the modulus [512]: 2048
 % Generating 2048 bit RSA keys, keys will be non-exportable...
 [OK] (elapsed time was 0 seconds)

5. Update the Ansible.cfg file with the following highlighted parameters:

$ cat Ansible.cfg
[defaults]
 host_key_checking=False