anchor.diff:            "fou"
             "xfrm"
             "ifb"
  +          "batadv"
           ])
           (assertByteFormat "MTUBytes")
           (assertMacAddress "MACAddress")
  
positive.code:         + optionalString (def.vrfConfig != { }) ''
            [VRF]
            ${attrsToSection def.vrfConfig}
          ''
          + def.extraConfig;
      };
  
negative.code:       '';
      };
  
      batmanAdvancedConfig = mkOption {
        default = {};
        example = {
          GatewayMode = "server";
          RoutingAlgorithm = "batman-v";
        };
        type = types.addCheck (types.attrsOf unitOption) check.netdev.sectionBatmanAdvanced;
        description = ''
          Each attribute in this set specifies an option in the
          <literal>[BatmanAdvanced]</literal> section of the unit. See
          <citerefentry><refentrytitle>systemd.netdev</refentrytitle>
          <manvolnum>5</manvolnum></citerefentry> for details.
        '';
      };
  
    };
  
    addressOptions = {
  