How to do it...

1. Create a new directory with the following name: ch2_ios.
2. Inside this new folder, create the hosts file with the following content:

$ cat hosts
 [access]
 access01 Ansible_host=172.20.1.18
 access02 Ansible_host=172.20.1.19

[core]
 core01 Ansible_host=172.20.1.20
 core02 Ansible_host=172.20.1.21

[wan]
 wan01 Ansible_host=172.20.1.22
 wan02 Ansible_host=172.20.1.23

[lan:children]
 access
 core

[network:children]
 lan
 wan

3. Create the Ansible.cfg file with the following content:

$ cat Ansible.cfg

[defaults]
 inventory=hosts
 retry_files_enabled=False
 gathering=explicit