diff --git a/flake.lock b/flake.lock
index f74a156..e7021b0 100644
--- a/flake.lock
+++ b/flake.lock
@@ -105,6 +105,27 @@
         "url": "https://git.clan.lol/clan/data-mesher/archive/main.tar.gz"
       }
     },
+    "devshell": {
+      "inputs": {
+        "nixpkgs": [
+          "nix-topology",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1728330715,
+        "narHash": "sha256-xRJ2nPOXb//u1jaBnDP56M7v5ldavjbtR6lfGqSvcKg=",
+        "owner": "numtide",
+        "repo": "devshell",
+        "rev": "dd6b80932022cea34a019e2bb32f6fa9e494dfef",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "devshell",
+        "type": "github"
+      }
+    },
     "disko": {
       "inputs": {
         "nixpkgs": [
@@ -146,6 +167,22 @@
         "type": "github"
       }
     },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1696426674,
+        "narHash": "sha256-kvjfFW7WAETZlt09AgDn1MrtKzP7t90Vf7vypd3OL1U=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "0f9255e01c2351cc7d116c072cb317785dd33b33",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
     "flake-parts": {
       "inputs": {
         "nixpkgs-lib": [
@@ -188,6 +225,46 @@
         "type": "github"
       }
     },
+    "flake-utils_2": {
+      "inputs": {
+        "systems": "systems_4"
+      },
+      "locked": {
+        "lastModified": 1726560853,
+        "narHash": "sha256-X6rJYSESBVr3hBoH0WbKE5KvhPU5bloyZ2L4K60/fPQ=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "c1dfcf08411b08f6b8615f7d8971a2bfa81d5e8a",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "gitignore": {
+      "inputs": {
+        "nixpkgs": [
+          "nix-topology",
+          "pre-commit-hooks",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1709087332,
+        "narHash": "sha256-HG2cCnktfHsKV0s4XW83gU3F57gaTljL9KNSuG6bnQs=",
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "rev": "637db329424fd7e46cf4185293b9cc8c88c95394",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "gitignore.nix",
+        "type": "github"
+      }
+    },
     "gvc": {
       "flake": false,
       "locked": {
@@ -317,6 +394,29 @@
         "url": "https://git.clan.lol/clan/nix-select/archive/main.tar.gz"
       }
     },
+    "nix-topology": {
+      "inputs": {
+        "devshell": "devshell",
+        "flake-utils": "flake-utils_2",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "pre-commit-hooks": "pre-commit-hooks"
+      },
+      "locked": {
+        "lastModified": 1744142264,
+        "narHash": "sha256-h5KyodobZm8dx/HSNN+basgdmjxrQxudjrss4gAQpZk=",
+        "owner": "oddlama",
+        "repo": "nix-topology",
+        "rev": "f49121cbbf4a86c560638ade406d99ee58deb7aa",
+        "type": "github"
+      },
+      "original": {
+        "owner": "oddlama",
+        "repo": "nix-topology",
+        "type": "github"
+      }
+    },
     "nixlib": {
       "locked": {
         "lastModified": 1736643958,
@@ -414,6 +514,33 @@
         "type": "github"
       }
     },
+    "pre-commit-hooks": {
+      "inputs": {
+        "flake-compat": "flake-compat",
+        "gitignore": "gitignore",
+        "nixpkgs": [
+          "nix-topology",
+          "nixpkgs"
+        ],
+        "nixpkgs-stable": [
+          "nix-topology",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1730797577,
+        "narHash": "sha256-SrID5yVpyUfknUTGWgYkTyvdr9J1LxUym4om3SVGPkg=",
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "rev": "1864030ed24a2b8b4e4d386a5eeaf0c5369e50a9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "cachix",
+        "repo": "pre-commit-hooks.nix",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "agenix": "agenix",
@@ -422,6 +549,7 @@
         "home-manager": "home-manager_2",
         "ignis": "ignis",
         "impermanence": "impermanence",
+        "nix-topology": "nix-topology",
         "nixos-generators": "nixos-generators",
         "nixos-hardware": "nixos-hardware",
         "nixpkgs": "nixpkgs_2"
@@ -493,6 +621,21 @@
         "type": "github"
       }
     },
+    "systems_4": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
     "treefmt-nix": {
       "inputs": {
         "nixpkgs": [
diff --git a/flake.nix b/flake.nix
index 9b4ff19..aec3202 100644
--- a/flake.nix
+++ b/flake.nix
@@ -92,6 +92,29 @@
               };
             }
           );
+
+      topology =
+        nixpkgs.lib.genAttrs
+          [
+            "x86_64-linux"
+            "aarch64-linux"
+          ]
+          (
+            system:
+            let
+              pkgs = import nixpkgs {
+                inherit system;
+                overlays = [ inputs.nix-topology.overlays.default ];
+              };
+            in
+            import inputs.nix-topology {
+              inherit pkgs;
+              modules = [
+                { inherit (self) nixosConfigurations; }
+                ./topology.nix
+              ];
+            }
+          );
     };
 
   inputs = {
@@ -127,6 +150,10 @@
       url = "github:linkfrg/ignis";
       inputs.nixpkgs.follows = "nixpkgs";
     };
+    nix-topology = {
+      url = "github:oddlama/nix-topology";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   nixConfig = {
diff --git a/machines/crocus/configuration.nix b/machines/crocus/configuration.nix
index 39e52d0..49f1674 100644
--- a/machines/crocus/configuration.nix
+++ b/machines/crocus/configuration.nix
@@ -12,6 +12,7 @@
     inputs.clan-core.clanModules.state-version
     ../../modules/remote-builder.nix
     ../../modules/borgbackup.nix
+    ./topology.nix
   ];
 
   nixpkgs.hostPlatform = "x86_64-linux";
diff --git a/machines/crocus/topology.nix b/machines/crocus/topology.nix
new file mode 100644
index 0000000..d658870
--- /dev/null
+++ b/machines/crocus/topology.nix
@@ -0,0 +1,11 @@
+{
+  topology.self = {
+    hardware.info = "x86_64 VPS";
+    interfaces = {
+      tailscale0 = {
+        type = "wireguard";
+        network = "tailscale";
+      };
+    };
+  };
+}
diff --git a/machines/genepi/configuration.nix b/machines/genepi/configuration.nix
index d373c90..5831449 100644
--- a/machines/genepi/configuration.nix
+++ b/machines/genepi/configuration.nix
@@ -19,6 +19,7 @@
     ./nginx.nix
     ./syncthing.nix
     ./taskchampion.nix
+    ./topology.nix
 
     ../../system
     ../../modules/borgbackup.nix
diff --git a/machines/genepi/topology.nix b/machines/genepi/topology.nix
new file mode 100644
index 0000000..184608a
--- /dev/null
+++ b/machines/genepi/topology.nix
@@ -0,0 +1,24 @@
+{ config, ... }:
+let
+  inherit (config.lib.topology)
+    mkConnection
+    ;
+in
+{
+  topology.self = {
+    hardware.info = "Raspberry Pi 4B";
+    interfaces = {
+      tailscale0 = {
+        type = "wireguard";
+        network = "tailscale";
+      };
+      enp1s0 = {
+        type = "ethernet";
+        network = "home";
+        physicalConnections = [
+          (mkConnection "cassoulet" "eth1")
+        ];
+      };
+    };
+  };
+}
diff --git a/machines/haze/configuration.nix b/machines/haze/configuration.nix
index d0b43f8..64ed0a1 100644
--- a/machines/haze/configuration.nix
+++ b/machines/haze/configuration.nix
@@ -18,6 +18,7 @@
     ./thunderbird.nix
     ./network.nix
     ./syncthing.nix
+    ./topology.nix
     ./video.nix
     ../../system
 
diff --git a/machines/haze/topology.nix b/machines/haze/topology.nix
new file mode 100644
index 0000000..8a2990a
--- /dev/null
+++ b/machines/haze/topology.nix
@@ -0,0 +1,12 @@
+{
+  topology.self = {
+    hardware.info = "VivoBook Laptop";
+    interfaces = {
+      tailscale0 = {
+        type = "wireguard";
+        network = "tailscale";
+        virtual = true;
+      };
+    };
+  };
+}
diff --git a/system/network/default.nix b/system/network/default.nix
index 1f59251..3f791d2 100644
--- a/system/network/default.nix
+++ b/system/network/default.nix
@@ -1,5 +1,7 @@
+{ inputs, ... }:
 {
   imports = [
+    inputs.nix-topology.nixosModules.default
     ./tailscale.nix
   ];
 }
diff --git a/topology.nix b/topology.nix
new file mode 100644
index 0000000..bd2d18b
--- /dev/null
+++ b/topology.nix
@@ -0,0 +1,40 @@
+{ config, ... }:
+let
+  inherit (config.lib.topology)
+    mkConnection
+    mkInternet
+    mkRouter
+    ;
+in
+{
+  nodes.internet = mkInternet {
+    connections = [
+      (mkConnection "cassoulet" "wan1")
+      (mkConnection "crocus" "enp1s0")
+    ];
+  };
+
+  nodes.cassoulet = mkRouter "Cassoulet" {
+    info = "BBox Fibre";
+    interfaceGroups = [
+      [ "wan1" ]
+      [
+        "eth1"
+        "eth2"
+        "eth3"
+        "eth4"
+      ]
+    ];
+  };
+
+  networks.home = {
+    name = "Home Network";
+    cidrv4 = "192.168.1.1/24";
+  };
+
+  networks.tailscale = {
+    name = "Tailscale";
+    cidrv4 = "100.100.181.10/32";
+    cidrv6 = "fd7a:115c:a1e0::2401:b50a/128";
+  };
+}