def _setup_subnet_parameters(self, params, data, is_create=True):
        """Setup subnet parameters

        This methods setups subnet parameters which are available
        in both create and update.
        """
        is_update = not is_create
        params['enable_dhcp'] = data['enable_dhcp']
        if int(data['ip_version']) == 6:
            ipv6_modes = utils.get_ipv6_modes_attrs_from_menu(
                data['ipv6_modes'])
            if ipv6_modes[0] and is_create:
                params['ipv6_ra_mode'] = ipv6_modes[0]
            if ipv6_modes[1] and is_create:
                params['ipv6_address_mode'] = ipv6_modes[1]
        if data['allocation_pools']:
            pools = [dict(zip(['start', 'end'], pool.strip().split(',')))
                     for pool in data['allocation_pools'].splitlines()
                     if pool.strip()]
            params['allocation_pools'] = pools
        if data['host_routes'] or is_update:
            routes = [dict(zip(['destination', 'nexthop'],
                               route.strip().split(',')))
                      for route in data['host_routes'].splitlines()
                      if route.strip()]
            params['host_routes'] = routes
        if data['dns_nameservers'] or is_update:
            nameservers = [ns.strip()
                           for ns in data['dns_nameservers'].splitlines()
                           if ns.strip()]
            params['dns_nameservers'] = nameservers
Setup subnet parameters

        This methods setups subnet parameters which are available
        in both create and update.