anchor.diff:          (assertMinimum "IPv6HopLimit" 0)
           (assertValueOneOf "IPv4ProxyARP" boolValues)
           (assertValueOneOf "IPv6ProxyNDP" boolValues)
  -        (assertValueOneOf "IPv6PrefixDelegation" ["static" "dhcpv6" "yes" "false"])
  +        (assertValueOneOf "IPv6SendRA" boolValues)
           (assertValueOneOf "DHCPv6PrefixDelegation" boolValues)
           (assertByteFormat "IPv6MTUBytes")
           (assertValueOneOf "ActiveSlave" boolValues)
  
positive.code: in
  
  {
  
    options = {
  
      systemd.network.enable = mkOption {
  
negative.code:           "IPv4ProxyARP"
            "IPv6ProxyNDP"
            "IPv6ProxyNDPAddress"
            "IPv6SendRA"
            "DHCPv6PrefixDelegation"
            "IPv6MTUBytes"
            "Bridge"
  