SSH times out when trying to validate Tempest authentication

[Sylvain Bauza]

Saw in the check-tempest-dsvm-neutron-full job, there is a test failing :

tempest.scenario.test_load_balancer_basic.TestLoadBalancerBasic.test_load_balancer_basic[compute,network]
2014-12-23 12:27:37.522 | ---------------------------------------------------------------------------------------------------------
2014-12-23 12:27:37.522 |
2014-12-23 12:27:37.522 | Captured traceback:
2014-12-23 12:27:37.522 | ~~~~~~~~~~~~~~~~~~~
2014-12-23 12:27:37.522 | Traceback (most recent call last):
2014-12-23 12:27:37.522 | File "tempest/test.py", line 112, in wrapper
2014-12-23 12:27:37.522 | return f(self, *func_args, **func_kwargs)
2014-12-23 12:27:37.522 | File "tempest/scenario/test_load_balancer_basic.py", line 315, in test_load_balancer_basic
2014-12-23 12:27:37.522 | self._start_servers()
2014-12-23 12:27:37.522 | File "tempest/scenario/test_load_balancer_basic.py", line 168, in _start_servers
2014-12-23 12:27:37.523 | private_key=private_key)
2014-12-23 12:27:37.523 | File "tempest/scenario/manager.py", line 325, in get_remote_client
2014-12-23 12:27:37.523 | linux_client.validate_authentication()
2014-12-23 12:27:37.523 | File "tempest/common/utils/linux/remote_client.py", line 55, in validate_authentication
2014-12-23 12:27:37.523 | self.ssh_client.test_connection_auth()
2014-12-23 12:27:37.523 | File "tempest/common/ssh.py", line 151, in test_connection_auth
2014-12-23 12:27:37.523 | connection = self._get_ssh_connection()
2014-12-23 12:27:37.523 | File "tempest/common/ssh.py", line 88, in _get_ssh_connection
2014-12-23 12:27:37.523 | password=self.password)
2014-12-23 12:27:37.523 | SSHTimeout: Connection to the 172.24.4.69 via SSH timed out.

Logstash shows multiple occurrences of the bug (425 in the last 24h) :

http://logstash.openstack.org/#eyJzZWFyY2giOiJtZXNzYWdlOlwidmlhIFNTSCB0aW1lZCBvdXRcIiIsImZpZWxkcyI6W10sIm9mZnNldCI6MCwidGltZWZyYW1lIjoiODY0MDAiLCJncmFwaG1vZGUiOiJjb3VudCIsInRpbWUiOnsidXNlcl9pbnRlcnZhbCI6MH0sInN0YW1wIjoxNDE5MzQ3MzM0MzY1fQ==