'Get name server data from fabric.
This method will return the connected node port wwn list(local
and remote) for the given switch fabric
show fcns database'

def get_nameserver_info(self):

    cli_output = None
    return_list = []
    try:
        cli_output = self._get_switch_info([ZoneConstant.FCNS_SHOW, self.fabric_vsan])
    except exception.CiscoZoningCliException:
        with excutils.save_and_reraise_exception():
            LOG.error('Failed    collecting    fcns    database    info    for    fabric    %s', self.switch_ip)
    if cli_output:
        return_list = self._parse_ns_output(cli_output)
    LOG.info('Connector    returning    fcnsinfo-%s', return_list)
    return return_list
