let
  mkUserVlan = id: rec {
    # on alloue 10.0.0.0/17 aux thurnés, avec un /27 chacun, on garde 10.0.0.0/27 pour nous (routeur et autres)
    vlan = 4094 - id;
    prefix24nb = (id + 1) / 8;
    prefix27nb = (id + 1 - prefix24nb * 8) * 32;
    prefixLength = 27;
    netIP = "10.0.${toString prefix24nb}.${toString prefix27nb}";
    servIP = "10.0.${toString prefix24nb}.${toString (prefix27nb + 1)}";
    broadIP = "10.0.${toString prefix24nb}.${toString (prefix27nb + 31)}";
    interfaceName = "vlan-user-${toString vlan}";
  };
in
builtins.genList mkUserVlan 300 # 850