code: def cfg_sync_routers(self, context, host, router_ids=None,
                           hosting_device_ids=None):
          
          adm_context = bc.context.get_admin_context()
          try:
              routers = (
                  self._l3plugin.list_active_sync_routers_on_hosting_devices(
                      adm_context, host, router_ids, hosting_device_ids))
          except AttributeError:
              routers = []
          LOG.debug('Routers returned to Cisco cfg agent@%(agt)s:\n %(routers)s',
                    {'agt': host, 'routers': jsonutils.dumps(routers, indent=5)})
          return routers
docs: Sync routers according to filters to a specific Cisco cfg agent.
  
          :param context: contains user information
          :param host: originator of callback
          :param router_ids: list of router ids to return information about
          :param hosting_device_ids: list of hosting device ids to get
              routers for.
          :returns: a list of routers with their hosting devices, interfaces and
              floating_ips