anchor.diff:              ${attrsToSection def.ipv6PrefixDelegationConfig}
   
             ''}
  +          ${flip concatMapStrings def.ipv6Prefixes (x: ''
  +            [IPv6Prefix]
  +            ${attrsToSection x.ipv6PrefixConfig}
  +
  +          '')}
             ${optionalString (def.dhcpServerConfig != { }) ''
               [DHCPServer]
               ${attrsToSection def.dhcpServerConfig}
  
positive.code:     (assertMinimum "DNSLifetimeSec" 0)
    ];
  
    checkDhcpServer = checkUnitConfig "DHCPServer" [
      (assertOnlyFields [
        "PoolOffset" "PoolSize" "DefaultLeaseTimeSec" "MaxLeaseTimeSec"
  
negative.code:     };
    };
  
    ipv6PrefixOptions = {
      options = {
        ipv6PrefixConfig = mkOption {
          default = {};
          example = { Prefix = "fd00::/64"; };
          type = types.addCheck (types.attrsOf unitOption) checkIpv6Prefix;
          description = ''
            Each attribute in this set specifies an option in the
            <literal>[IPv6Prefix]</literal> section of the unit.  See
            <citerefentry><refentrytitle>systemd.network</refentrytitle>
            <manvolnum>5</manvolnum></citerefentry> for details.
          '';
        };
      };
    };
  
  
    networkOptions = commonNetworkOptions // {
  
  