diff --git a/flake.nix b/flake.nix
index c1a5a3a8..8df2c96c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -223,27 +223,8 @@
     let
       inherit (nixos) lib;
 
-      extractZwHosts = { hosts4, hosts6, ... }:
-        lib.recursiveUpdate (
-          builtins.foldl' (result: name:
-            lib.recursiveUpdate result {
-              "${name}".ip4 = hosts4."${name}";
-            }
-          ) {} (builtins.attrNames hosts4)
-        ) (
-          builtins.foldl' (result: ctx:
-            builtins.foldl' (result: name:
-              lib.recursiveUpdate result {
-                "${name}".ip6 = hosts6."${ctx}"."${name}";
-              }
-            ) result (builtins.attrNames hosts6."${ctx}")
-          ) {} (builtins.attrNames hosts6)
-        );
+      inherit (import ./lib/network.nix { inherit lib zentralwerk; }) hostRegistry;
 
-      hostRegistry =
-        builtins.foldl' (result: net:
-          lib.recursiveUpdate result (extractZwHosts zentralwerk.lib.config.site.net."${net}")
-        ) {} [ "core" "cluster" "c3d2" "serv" "flpk" "pub" ];
 
       overlayList = [
         self.overlays
diff --git a/lib/network.nix b/lib/network.nix
new file mode 100644
index 00000000..7cab5988
--- /dev/null
+++ b/lib/network.nix
@@ -0,0 +1,25 @@
+{ lib, zentralwerk }:
+
+rec {
+  extractZwHosts = { hosts4, hosts6, ... }:
+    lib.recursiveUpdate (
+      builtins.foldl' (result: name:
+        lib.recursiveUpdate result {
+          "${name}".ip4 = hosts4."${name}";
+        }
+      ) {} (builtins.attrNames hosts4)
+    ) (
+      builtins.foldl' (result: ctx:
+        builtins.foldl' (result: name:
+          lib.recursiveUpdate result {
+            "${name}".ip6 = hosts6."${ctx}"."${name}";
+          }
+        ) result (builtins.attrNames hosts6."${ctx}")
+      ) {} (builtins.attrNames hosts6)
+    );
+
+  hostRegistry =
+    builtins.foldl' (result: net:
+      lib.recursiveUpdate result (extractZwHosts zentralwerk.lib.config.site.net."${net}")
+    ) {} [ "core" "cluster" "c3d2" "serv" "flpk" "pub" ];
+}