'assert ping server via source ssh connection
Note: This is an internal method.  Use check_remote_connectivity
instead.
:param source: RemoteClient: an ssh connection from which to ping
:param dest: and IP to ping against
:param should_succeed: boolean should ping succeed or not
:param nic: specific network interface to ping from'

def _check_remote_connectivity(self, source, dest, should_succeed=True, nic=None):

    def ping_remote():
        try:
            source.ping_host(dest, nic=nic)
        except lib_exc.SSHExecCommandFailed:
            LOG.warning('Failed    to    ping    IP:    %s    via    a    ssh    connection    from:    %s.', dest, source.ssh_client.host)
            return (not should_succeed)
        return should_succeed
    return test_utils.call_until_true(ping_remote, CONF.validation.ping_timeout, 1)
