How to do it...

1. Create a new playbook called ansible_loops.yml inside the ch1_ansible folder.
2. Inside the group_vars/cisco.yml file, incorporate the following content:

snmp_servers:
  - 10.1.1.1
  - 10.2.1.1

3. Inside the group_vars/juniper.yml file, incorporate the following content:

users:
  admin: admin123
  oper: oper123

4. Inside the ansible_loops.yml file, incorporate the following content:

---
  - name: Ansible Loop over a List
    hosts: cisco
    gather_facts: no
    tasks:
      - name: Loop over SNMP Servers
        debug:
          msg: "Router {{ hostname }} with snmp server {{ item }}"
        loop: "{{ snmp_servers}}"

  - name: Ansible Loop over a Dictionary
    hosts: juniper
    gather_facts: no
    tasks:
      - name: Loop over Username and Passowrds
        debug:
          msg: "Router {{ hostname }} with user {{ item.key }} password {{ item.value }}"
        with_dict: "{{ users}}"

5. Run the playbook as shown here:

$ ansible-playbook ansible_loops.yml -i hosts