Ansible com o Switch da Cisco

Olá,

Estou testando o Ansible para autotomizar alguns processos na empresa. Fui efetuar um teste simples (https://github.com/brona/ansible-cisco-ios-example), mas apresenta o seguinte erro de autenticação:

The full traceback is:
Traceback (most recent call last):
  File "/usr/bin/ansible-connection", line 105, in start
    self.connection._connect()
  File "/usr/lib/python2.7/site-packages/ansible/plugins/connection/network_cli.py", line 298, in _connect
    ssh = self.paramiko_conn._connect()
  File "/usr/lib/python2.7/site-packages/ansible/plugins/connection/paramiko_ssh.py", line 249, in _connect
    self.ssh = SSH_CONNECTION_CACHE[cache_key] = self._connect_uncached()
  File "/usr/lib/python2.7/site-packages/ansible/plugins/connection/paramiko_ssh.py", line 365, in _connect_uncached
    raise AnsibleConnectionFailure(msg)
AnsibleConnectionFailure: ('Bad authentication type', [u'publickey']) (allowed_types=[u'publickey'])

fatal: [172.16.0.6]: FAILED! => {
    "msg": "('Bad authentication type', [u'publickey']) (allowed_types=[u'publickey'])"

Tentei efetuar essas configurações (https://docs.ansible.com/ansible/2.5/modules/authorized_key_module.html), mas sem sucesso.

O que eu posso fazer para autenticar sem usar o arquivo authorized_keys?