diff --git a/hosts/g2/configuration.nix b/hosts/g2/configuration.nix
index f98820f..1bb2cd9 100644
--- a/hosts/g2/configuration.nix
+++ b/hosts/g2/configuration.nix
@@ -7,8 +7,10 @@
       ../modules/nasp.nix
     ];
   nasp = {
-    serial = 2;
-    network = {
+    enable = true;
+    gSeries = {
+      enable = true;
+      serial = 2;
       eth0Name = "eno1";
       eth1Name = "eno2";
       eth2Name = "enp2s0np0";
diff --git a/hosts/modules/nasp.nix b/hosts/modules/nasp.nix
index 8a423d8..1ca80a1 100644
--- a/hosts/modules/nasp.nix
+++ b/hosts/modules/nasp.nix
@@ -2,18 +2,18 @@
 
 let
   mainCfg = config.nasp;
-  networkCfg = mainCfg.network;
-  hostName = ("g" + (builtins.toString mainCfg.serial));
-  ipSuffix = (builtins.toString (mainCfg.serial + 100));
+  gCfg = mainCfg.gSeries;
   dnew = (pkgs.writeShellScriptBin "dnew" (builtins.readFile ./scripts/dnew));
 in
 {
   options.nasp = {
-    serial = lib.mkOption {
-      type = lib.types.int;
-      description = "Serial of the machine (gX)";
-    };
-    network = {
+    enable = lib.mkEnableOption "the nasp server configurations";
+    gSeries = {
+      enable = lib.mkEnableOption "the g-series server configurations";
+      serial = lib.mkOption {
+        type = lib.types.int;
+        description = "Serial of the machine (gX)";
+      };
       eth0Name = lib.mkOption {
         type = lib.types.str;
         description = "Name of eth0 (192.168.16.0/24)";
@@ -30,220 +30,230 @@ in
   };
 
   # inplementation
-  config = {
-  nix.settings.experimental-features = [ "nix-command" "flakes" ];
-  nix.settings.substituters = [ "https://mirrors.tuna.tsinghua.edu.cn/nix-channels/store" ];
-  ## system config
-  boot.loader.systemd-boot.enable = true;
-  boot.loader.efi.canTouchEfiVariables = true;
-  time.hardwareClockInLocalTime = true;
-  networking.hostName = assert (mainCfg.serial > 0); hostName;
-  networking.search = [ "nasp" ];
-  i18n.defaultLocale = "C.UTF-8";
-  i18n.extraLocaleSettings = lib.mkDefault {
-    LC_ADDRESS = "zh_CN.UTF-8";
-    LC_IDENTIFICATION = "zh_CN.UTF-8";
-    LC_MEASUREMENT = "zh_CN.UTF-8";
-    LC_MONETARY = "zh_CN.UTF-8";
-    LC_NAME = "zh_CN.UTF-8";
-    LC_NUMERIC = "zh_CN.UTF-8";
-    LC_PAPER = "zh_CN.UTF-8";
-    LC_TELEPHONE = "zh_CN.UTF-8";
-    LC_TIME = "zh_CN.UTF-8";
-  };
-  time.timeZone = lib.mkDefault "Asia/Shanghai";
-  ## networking
-  networking.nameservers = [ "192.168.16.118" ];
-  services.resolved.enable = true;
-  networking.networkmanager.enable = false;
-  networking.useDHCP = false;
-  systemd.network.enable = true;
-  systemd.network.networks."10-eth0" = {
-    matchConfig.Name = networkCfg.eth0Name;
-    networkConfig = {
-      DHCP = "no";
-      IPv6AcceptRA = true;
-    };
-    address = [ "192.168.16.${ipSuffix}/24" ];
-    routes = [
-      {
-        routeConfig = {
-          Gateway = "192.168.16.118";
-          GatewayOnLink = true;
-          Metric = 90;
-        };
-      }
-      {
-        routeConfig = {
-          Gateway = "2001:da8:bf:300::1";
-          GatewayOnLink = true;
-          Metric = 90;
-        };
-      }
-    ];
-  };
-  systemd.network.networks."10-eth1" = {
-    matchConfig.Name = networkCfg.eth1Name;
-    networkConfig = {
-      DHCP = "yes";
-      IPv6AcceptRA = true;
-    };
-  };
-  systemd.network.networks."10-eth2" = {
-    matchConfig.Name = networkCfg.eth2Name;
-    address = [ "12.12.12.${ipSuffix}/24" ];
-  };
-  networking.interfaces.eno1.wakeOnLan.enable = true;
-  networking.extraHosts = ''
-    192.168.16.101 g1-nasp g1
-    192.168.16.102 g2-nasp g2
-    192.168.16.103 g3-nasp g3
-    192.168.16.104 g4-nasp g4
-    192.168.16.105 g5-nasp g5
-    192.168.16.106 g6-nasp g6
-    192.168.16.107 g7-nasp g7
-    192.168.16.108 g8-nasp g8
-    192.168.16.109 g9-nasp g9
-    192.168.16.110 g10-nasp g10
-    192.168.16.111 g11-nasp g11
-    192.168.16.112 g12-nasp g12
-    192.168.16.113 g13-nasp g13
-    192.168.16.114 g14-nasp g14
-    192.168.16.115 g15-nasp g15
-    192.168.16.116 g16-nasp g16
-    192.168.16.117 g17-nasp g17
-    192.168.16.118 g18-nasp g18 nasp.fit git.nasp.fit
-    192.168.16.119 g19-nasp g19
-    192.168.16.120 g20-nasp g20
-  '';
-  networking.firewall = {
-    allowedTCPPorts = [ 12022 ];
-    extraCommands = ''
-      iptables -A INPUT -s 192.168.16.0/24 -j ACCEPT
-      iptables -A INPUT -s 12.12.12.0/24 -j ACCEPT
-    '';
-  };
-  networking.rxe = {
-    enable = true;
-    interfaces = [ "${networkCfg.eth2Name}" ];
-  };
-  ## packages and services
-  nixpkgs.config.allowUnfree = true;
-  environment.systemPackages = with pkgs; [
-    bash cmake curl file fzf gcc git gnumake htop nettools inetutils iproute2 iputils less man
-    openssh openssl python3 rdma-core sops sudo tmux util-linux vim wget zsh
-    # extended
-    acpi atop btop dialog dig dmidecode dos2unix ethtool fish iftop iotop killall lshw lsof
-    mtr netcat-gnu nethogs nmap pciutils plocate pstree pwgen ripgrep smartmontools socat
-    sysstat tcpdump unzip usbutils virt-what zip
-    # full
-    wireshark zmap
-    # custom
-    dnew
-  ];
-  programs.zsh.enable = true;
-  services.cron.enable = true;
-  systemd.timers."registry" = {
-    wantedBy = [ "timers.target" ];
-    timerConfig = {
-      OnCalendar = "*:0/5:0";
-      Unit = "registry.service";
-    };
-  };
-  systemd.services."registry" = {
-    serviceConfig = {
-      Type = "oneshot";
-      User = "root";
-    };
-    script = builtins.readFile ./scripts/registry.sh;
-    path = [ pkgs.git pkgs.bash pkgs.su ];
-  };
-  ## user config
-  users.users.root.shell = pkgs.zsh;
-  ## dotfiles.cn
-  system.activationScripts.dotfilesSetup.text = ''
-    if [ -d ~ -a ! -e ~/dotfiles/update.sh ]; then
-      source ${config.system.build.setEnvironment}
-      rm -rf ~/dotfiles
-      bash <(curl -fsSL dotfiles.cn)
-    fi
-  '';
-  ## server
-  services.openssh.enable = true;
-  services.openssh.settings.PermitRootLogin = "prohibit-password";
-  services.openssh.authorizedKeysFiles = [ ".ssh/authorized_keys2" ];
-  services.openssh.ports = [ 12022 ];
-  systemd.targets.sleep.enable = false;
-  systemd.targets.suspend.enable = false;
-  systemd.targets.hibernate.enable = false;
-  systemd.targets.hybrid-sleep.enable = false;
-  ## xserver
-  services.xserver = {
-    enable = true;
-    videoDrivers = [ "nvidia" ];
-    displayManager.gdm.enable = true;
-    desktopManager.gnome = {
-      enable = true;
-      extraGSettingsOverridePackages = [ pkgs.gnome.mutter ];
-      extraGSettingsOverrides = ''
-        [org.gnome.mutter]
-        experimental-features=['scale-monitor-framebuffer']
+  config = lib.mkIf mainCfg.enable (lib.mkMerge [
+    # base
+    {
+      ## nix
+      nix.settings.experimental-features = [ "nix-command" "flakes" ];
+      nix.settings.substituters = [ "https://mirrors.tuna.tsinghua.edu.cn/nix-channels/store" ];
+      ## hardware and system
+      boot.loader.systemd-boot.enable = true;
+      boot.loader.efi.canTouchEfiVariables = true;
+      time.hardwareClockInLocalTime = true;
+      i18n.defaultLocale = "C.UTF-8";
+      i18n.extraLocaleSettings = lib.mkDefault {
+        LC_ADDRESS = "zh_CN.UTF-8";
+        LC_IDENTIFICATION = "zh_CN.UTF-8";
+        LC_MEASUREMENT = "zh_CN.UTF-8";
+        LC_MONETARY = "zh_CN.UTF-8";
+        LC_NAME = "zh_CN.UTF-8";
+        LC_NUMERIC = "zh_CN.UTF-8";
+        LC_PAPER = "zh_CN.UTF-8";
+        LC_TELEPHONE = "zh_CN.UTF-8";
+        LC_TIME = "zh_CN.UTF-8";
+      };
+      time.timeZone = lib.mkDefault "Asia/Shanghai";
+      ## network
+      services.resolved.enable = true;
+      networking.networkmanager.enable = false;
+      networking.useDHCP = false;
+      systemd.network.enable = true;
+      networking.firewall.allowedTCPPorts = [ 12022 ];
+      ## packages and services
+      nixpkgs.config.allowUnfree = true;
+      environment.systemPackages = with pkgs; [
+        bash cmake curl file fzf gcc git gnumake htop nettools inetutils iproute2 iputils less man
+        openssh openssl python3 rdma-core sops sudo tmux util-linux vim wget zsh
+        # extended
+        acpi atop btop dialog dig dmidecode dos2unix ethtool fish iftop iotop killall lshw lsof
+        mtr netcat-gnu nethogs nmap pciutils plocate pstree pwgen ripgrep smartmontools socat
+        sysstat tcpdump unzip usbutils virt-what zip
+        # full
+        wireshark zmap
+      ];
+      programs.zsh.enable = true;
+      services.cron.enable = true;
+      services.openssh.enable = true;
+      services.openssh.settings.PermitRootLogin = "prohibit-password";
+      services.openssh.authorizedKeysFiles = [ ".ssh/authorized_keys2" ];
+      services.openssh.ports = [ 12022 ];
+      systemd.targets.sleep.enable = false;
+      systemd.targets.suspend.enable = false;
+      systemd.targets.hibernate.enable = false;
+      systemd.targets.hybrid-sleep.enable = false;
+      ## users
+      users.mutableUsers = true;
+      users.users.root.openssh.authorizedKeys.keys = [
+        "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCUN7IXF4nlFcVfgHesgik3LIAiXlVMYJPm3yD13EVarQx5jqdBgk8Dwgkgf4rPO6MFpvIpinOyEO8zOS6HHQrCLZUv5yTFaDkUuB7eQ0EmpicGbmk9bHqj1HkOZxaobkpEfQUmFKYvkp4EexVw66sO0qfXvjHZ4H6yCAJLK5aUnKfgrE8tODzP82sU/mpJjW+Pq3uanNq754gaHwhxCIXG143/zp8qzBAeKe38xVqqDq9fTkG4hvzFvkRdS88i6l1z++0P3n0HGdOjtSg7P7fO7+7ZyPYr0gO5vB720Om/zxqPrGd9cicWi4P+aVKa+0ujWH/pqufWG6uCjKWHnBs7 sk0/piv/9a"
+        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHLYgVj+NPino6sOmahULN7SbAMaVAgzqPfDjz2S8zDv pc1/windows"
+        "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKhS4voo3K/Dvzqckr0bouO1WkCI5XxswstHWnuuyKBz ltp1-bd"
+      ];
+      users.users.root.shell = pkgs.zsh;
+      system.activationScripts.dotfilesSetup.text = ''
+        if [ -d ~ -a ! -e ~/dotfiles/update.sh ]; then
+          source ${config.system.build.setEnvironment}
+          rm -rf ~/dotfiles
+          bash <(curl -fsSL dotfiles.cn)
+        fi
       '';
-    };
-    layout = "us";
-    xkbVariant = "";
-  };
-  ## docker
-  virtualisation.docker = {
-    enable = true;
-    enableNvidia = true;
-    daemon.settings = {
-      ipv6 = true;
-      fixed-cidr-v6 = "fddd:d0c1:1::/64";
-      experimental = true;
-      ip6tables = true;
-      live-restore = false;
-    };
-  };
-  nixpkgs.config.nvidia.acceptLicense = true;
-  hardware.nvidia = {
-    package = config.boot.kernelPackages.nvidiaPackages.legacy_470;
-    modesetting.enable = true;
-    powerManagement.enable = false;
-    powerManagement.finegrained = false;
-    open = false;
-    nvidiaSettings = true;
-  };
-  hardware.opengl = {
-    enable = true;
-    driSupport = true;
-    driSupport32Bit = true;
-  };
-  ## users
-  users.mutableUsers = true;
-  users.users.root.openssh.authorizedKeys.keys = [
-    "ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCUN7IXF4nlFcVfgHesgik3LIAiXlVMYJPm3yD13EVarQx5jqdBgk8Dwgkgf4rPO6MFpvIpinOyEO8zOS6HHQrCLZUv5yTFaDkUuB7eQ0EmpicGbmk9bHqj1HkOZxaobkpEfQUmFKYvkp4EexVw66sO0qfXvjHZ4H6yCAJLK5aUnKfgrE8tODzP82sU/mpJjW+Pq3uanNq754gaHwhxCIXG143/zp8qzBAeKe38xVqqDq9fTkG4hvzFvkRdS88i6l1z++0P3n0HGdOjtSg7P7fO7+7ZyPYr0gO5vB720Om/zxqPrGd9cicWi4P+aVKa+0ujWH/pqufWG6uCjKWHnBs7 sk0/piv/9a"
-    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIHLYgVj+NPino6sOmahULN7SbAMaVAgzqPfDjz2S8zDv pc1/windows"
-    "ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIKhS4voo3K/Dvzqckr0bouO1WkCI5XxswstHWnuuyKBz ltp1-bd"
-  ];
-  users.users.nasp = {
-    isNormalUser = true;
-    createHome = true;
-    group = "nasp";
-    extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
-    packages = with pkgs; [
-      firefox
-    ];
-    hashedPassword = "$y$j9T$Ei67I7VhQD6gF20/lNBUx0$jnrLqLNSJVCS959deKCamoOi4Q76nNeQ7/kDQCCABl1";
-  };
-  users.groups.nasp = {};
-  security.sudo.extraConfig = ''
-    %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/docker
-    %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/reboot
-    %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/whoami
-    %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/nvidia-smi
-    %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/shutdown
-    %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/ip
-  '';
-  };
+      users.users.nasp = {
+        isNormalUser = true;
+        createHome = true;
+        group = "nasp";
+        extraGroups = [ "wheel" ]; # Enable ‘sudo’ for the user.
+        packages = with pkgs; [
+          firefox
+        ];
+        hashedPassword = "$y$j9T$Ei67I7VhQD6gF20/lNBUx0$jnrLqLNSJVCS959deKCamoOi4Q76nNeQ7/kDQCCABl1";
+      };
+      users.groups.nasp = {};
+    }
+    # g series
+    (lib.mkIf (gCfg.enable) let
+      ipSuffix = (builtins.toString (gCfg.serial + 100));
+    in {
+      ## hardware
+      nixpkgs.config.nvidia.acceptLicense = true;
+      hardware.nvidia = {
+        package = config.boot.kernelPackages.nvidiaPackages.legacy_470;
+        modesetting.enable = true;
+        powerManagement.enable = false;
+        powerManagement.finegrained = false;
+        open = false;
+        nvidiaSettings = true;
+      };
+      hardware.opengl = {
+        enable = true;
+        driSupport = true;
+        driSupport32Bit = true;
+      };
+      ## network
+      networking.hostName = assert (gCfg.serial > 0); "g" + (builtins.toString gCfg.serial);
+      networking.search = [ "nasp" ];
+      networking.nameservers = [ "192.168.16.118" ];
+      systemd.network.networks."10-eth0" = {
+        matchConfig.Name = gCfg.eth0Name;
+        networkConfig = {
+          DHCP = "no";
+          IPv6AcceptRA = true;
+        };
+        address = [ "192.168.16.${ipSuffix}/24" ];
+        routes = [
+          {
+            routeConfig = {
+              Gateway = "192.168.16.118";
+              GatewayOnLink = true;
+              Metric = 90;
+            };
+          }
+          {
+            routeConfig = {
+              Gateway = "2001:da8:bf:300::1";
+              GatewayOnLink = true;
+              Metric = 90;
+            };
+          }
+        ];
+      };
+      systemd.network.networks."10-eth1" = {
+        matchConfig.Name = gCfg.eth1Name;
+        networkConfig = {
+          DHCP = "yes";
+          IPv6AcceptRA = true;
+        };
+      };
+      systemd.network.networks."10-eth2" = {
+        matchConfig.Name = gCfg.eth2Name;
+        address = [ "12.12.12.${ipSuffix}/24" ];
+      };
+      networking.interfaces.${gCfg.eth0Name}.wakeOnLan.enable = true;
+      networking.extraHosts = ''
+        192.168.16.101 g1-nasp g1
+        192.168.16.102 g2-nasp g2
+        192.168.16.103 g3-nasp g3
+        192.168.16.104 g4-nasp g4
+        192.168.16.105 g5-nasp g5
+        192.168.16.106 g6-nasp g6
+        192.168.16.107 g7-nasp g7
+        192.168.16.108 g8-nasp g8
+        192.168.16.109 g9-nasp g9
+        192.168.16.110 g10-nasp g10
+        192.168.16.111 g11-nasp g11
+        192.168.16.112 g12-nasp g12
+        192.168.16.113 g13-nasp g13
+        192.168.16.114 g14-nasp g14
+        192.168.16.115 g15-nasp g15
+        192.168.16.116 g16-nasp g16
+        192.168.16.117 g17-nasp g17
+        192.168.16.118 g18-nasp g18 nasp.fit git.nasp.fit
+        192.168.16.119 g19-nasp g19
+        192.168.16.120 g20-nasp g20
+      '';
+      networking.firewall.extraCommands = ''
+        iptables -A INPUT -s 192.168.16.0/24 -j ACCEPT
+        iptables -A INPUT -s 12.12.12.0/24 -j ACCEPT
+      '';
+      networking.rxe = {
+        enable = true;
+        interfaces = [ "${networkCfg.eth2Name}" ];
+      };
+      ## packages and services
+      environment.systemPackages = with pkgs; [
+        # custom
+        dnew
+      ];
+      systemd.timers."registry" = {
+        wantedBy = [ "timers.target" ];
+        timerConfig = {
+          OnCalendar = "*:0/5:0";
+          Unit = "registry.service";
+        };
+      };
+      systemd.services."registry" = {
+        serviceConfig = {
+          Type = "oneshot";
+          User = "root";
+        };
+        script = builtins.readFile ./scripts/registry.sh;
+        path = with pkgs; [ git bash su ];
+      };
+      ## desktop
+      services.xserver = {
+        enable = true;
+        videoDrivers = [ "nvidia" ];
+        displayManager.gdm.enable = true;
+        desktopManager.gnome = {
+          enable = true;
+          extraGSettingsOverridePackages = [ pkgs.gnome.mutter ];
+          extraGSettingsOverrides = ''
+            [org.gnome.mutter]
+            experimental-features=['scale-monitor-framebuffer']
+          '';
+        };
+        layout = "us";
+        xkbVariant = "";
+      };
+      ## docker
+      virtualisation.docker = {
+        enable = true;
+        enableNvidia = true;
+        daemon.settings = {
+          ipv6 = true;
+          fixed-cidr-v6 = "fddd:d0c1:1::/64";
+          experimental = true;
+          ip6tables = true;
+          live-restore = false;
+        };
+      };
+      ## users
+      security.sudo.extraConfig = ''
+        %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/docker
+        %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/reboot
+        %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/whoami
+        %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/nvidia-smi
+        %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/shutdown
+        %nasp ALL = (root) NOPASSWD: /run/current-system/sw/bin/ip
+      '';
+    })
+  ]);
 }