NixOSで冗長接続を制限する方法は？

必要なくNixOSのconfiguration.nixで次のようなPuppetを実装できますかnetworking.firewall.extraCommands？

firewall { '200 limit incoming SSH connections to 6 per minute':
  dport     => 22,
  proto     => tcp,
  recent    => update,
  rseconds  => 60,
  rhitcount => 6,
  rname     => 'SSH',
  rsource   => true,
  action    => drop,
} -> firewall { '201 allow incoming SSH connections':
  dport   => 22,
  proto   => tcp,
  recent  => set,
  rname   => 'SSH',
  rsource => true,
  action  => accept,
}