diff --git a/lib/default.nix b/lib/default.nix
index ca7c9ee..52171ce 100644
--- a/lib/default.nix
+++ b/lib/default.nix
@@ -1,5 +1,7 @@
-{lib}: {
-  imports=[./net.nix];
+{lib}:let 
+  net = import ./net.nix {inherit lib;};
+in
+{
 
   dirToStrings = dir: (map (v: builtins.readFile "${dir}/${v}")
     (builtins.filter (v:
@@ -11,4 +13,10 @@
         )
       else []
     )));
+
+
+  calcSystemdDhcpPoolOffset = {base, start, end}: {
+    offset = net.lib.net.ip.diff start base;
+    size = net.lib.net.ip.diff end start;
+  };
 }
diff --git a/modules/nixos/default.nix b/modules/nixos/default.nix
deleted file mode 100644
index 4da28bd..0000000
--- a/modules/nixos/default.nix
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  config,
-  pkgs,
-  lib,
-  inputs,
-  ...
-}: {
-  imports=[./systemd-dhcpServ.nix];
-}
diff --git a/modules/nixos/systemd-dhcpServ.nix b/modules/nixos/systemd-dhcpServ.nix
deleted file mode 100644
index 9e85bce..0000000
--- a/modules/nixos/systemd-dhcpServ.nix
+++ /dev/null
@@ -1,108 +0,0 @@
-{
-  config,
-  pkgs,
-  lib,
-  inputs,
-  ...
-}: {
-  options = {
-    host.systemdDhcpSrv = {
-      enable = lib.mkEnableOption "systemd DHCP server";
-
-      interface = lib.mkOption {
-        type = lib.types.str;
-        description = "interface to run dhcp server on";
-      };
-
-      uplinkInterface = lib.mkOption {
-        type = lib.types.str;
-        description = "if dns, router, or ntp are set but no adresses are set, pass on the settings of this interface.";
-        default = ":auto";
-      };
-
-      pool = lib.mkOption {
-        description = "the pool of ips the dhcp server will hand out.";
-        type = lib.types.submodule {
-          options = {
-            start = lib.mkOption {
-              type = lib.types.str;
-              description = "starting IP of the range the dhcp server will assign";
-            };
-            end = lib.mkOption {
-              type = lib.types.str;
-              description = "ending IP of the range the dhcp server will assign";
-            };
-          };
-        };
-      };
-
-      time = lib.mkOption {
-        type = lib.types.submodule {
-          options = {
-            default = lib.mkOption {
-              description = "the default dhcp lease time, in seconds, defaults to 1h";
-              type = lib.types.nullOr lib.types.int;
-              default = null;
-            };
-            max = lib.mkOption {
-              description = "the max dhcp lease time, in seconds. defaults to 12h";
-              type = lib.types.nullOr lib.types.int;
-              default = null;
-            };
-          };
-        };
-      };
-
-      dns = lib.mkoption {
-        type = lib.types.submodule {
-          options = {
-            enable = lib.mkOption {
-              type = lib.types.bool;
-              default = true;
-              description = "whether to include dns server info in the dhcp lease";
-            };
-            servers = lib.mkOption {
-              type = lib.types.listOf lib.types.str;
-              description = "IPs of dns servers to hand out";
-              default = [];
-            };
-          };
-        };
-      };
-
-      router = lib.mkoption {
-        type = lib.types.submodule {
-          options = {
-            enable = lib.mkOption {
-              type = lib.types.bool;
-              default = true;
-              description = "whether to include router (gateway) info in the dhcp lease";
-            };
-            servers = lib.mkOption {
-              type = lib.types.listOf lib.types.str;
-              description = "IPs of dns servers to hand out";
-              default = [];
-            };
-          };
-        };
-      };
-
-      ntp = lib.mkoption {
-        type = lib.types.submodule {
-          options = {
-            enable = lib.mkOption {
-              type = lib.types.bool;
-              default = true;
-              description = "whether to include ntp server info in the dhcp lease";
-            };
-            servers = lib.mkOption {
-              type = lib.types.listOf lib.types.str;
-              description = "IPs of ntp servers to hand out";
-              default = [];
-            };
-          };
-        };
-      };
-    };
-  };
-}