code: def _select_mgmt_networks(self, conf):
          nets = conf['nets']
          mgmts = sorted(
              [
                  name for name, net in nets.iteritems()
                  if net.get('management') is True
              ]
          )
          if len(mgmts) == 0:
              mgmt_name = sorted((nets.keys()))[0]
              LOGGER.debug(
                  'No management network configured, selecting network %s',
                  mgmt_name
              )
              nets[mgmt_name]['management'] = True
              mgmts.append(mgmt_name)
          for mgmt_name in mgmts:
              if nets[mgmt_name].get('dns_domain_name', None) is None:
                  nets[mgmt_name]['dns_domain_name'] = 'lago.local'
          return mgmts