diff --git a/hosts/carbon/configuration.nix b/hosts/carbon/configuration.nix
index 29e00ca..496db0f 100644
--- a/hosts/carbon/configuration.nix
+++ b/hosts/carbon/configuration.nix
@@ -79,8 +79,6 @@
 
   ipv6 table ospf6;
   ipv4 table ospf4;
-  ipv6 table bgp6;
-  ipv4 table bgp4;
 
   protocol direct direct_lo {
     interface "lo";
@@ -126,30 +124,6 @@
     };
   }
 
-  protocol kernel kernel_bgp6 {
-    kernel table 2000;
-    ipv6 {
-      table bgp6;
-      export filter {
-        krt_prefsrc=${ (lib.head config.networking.interfaces.lo.ipv6.addresses).address };
-        accept;
-      };
-      import none;
-    };
-  }
-
-  protocol kernel kernel_bgp4 {
-    kernel table 2000;
-    ipv4 {
-      table bgp4;
-      export filter {
-        krt_prefsrc=${ (lib.head config.networking.interfaces.lo.ipv4.addresses).address };
-        accept;
-      };
-      import none;
-    };
-  }
-
   protocol ospf v3 ospf_6 {
     ipv6 {
       table ospf6;
@@ -178,50 +152,6 @@
     };
   }
 
-  template bgp ibgp6 {
-    local as 4200002574;
-    graceful restart on;
-    source address ${ (lib.head config.networking.interfaces.lo.ipv6.addresses).address };
-    ipv6 {
-      table bgp6;
-      igp table ospf6;
-      next hop self;
-      import keep filtered;
-      import all;
-      export all;
-    };
-  }
-
-  template bgp ibgp4 {
-    local as 4200002574;
-    graceful restart on;
-    source address ${ (lib.head config.networking.interfaces.lo.ipv4.addresses).address };
-    ipv4 {
-      table bgp4;
-      igp table ospf4;
-      next hop self;
-      import keep filtered;
-      import all;
-      export all;
-    };
-  }
-
-  protocol bgp bgp_nonat6 from ibgp6 {
-    neighbor fd00:152:152:103::1 as 4200002574;
-  }
-
-  protocol bgp bgp_nonat4 from ibgp4 {
-    neighbor 10.152.103.1 as 4200002574;
-  }
-
-  protocol bgp bgp_porter6 from ibgp6 {
-    neighbor fd00:152:152:102::1 as 4200002574;
-  }
-
-  protocol bgp bgp_porter4 from ibgp4 {
-    neighbor 10.152.102.1 as 4200002574;
-  }
-
   protocol device {
     scan time 10;
   }
diff --git a/hosts/nonat/configuration.nix b/hosts/nonat/configuration.nix
index f4fd11a..9980438 100644
--- a/hosts/nonat/configuration.nix
+++ b/hosts/nonat/configuration.nix
@@ -87,22 +87,6 @@
 
   ipv6 table ospf6;
   ipv4 table ospf4;
-  ipv6 table bgp6;
-  ipv4 table bgp4;
-
-  protocol static static_bgp6 {
-    ipv6 {
-      table bgp6;
-    };
-    route 2001:638:904::/48 via ${config.networking.defaultGateway6.address};
-  }
-
-  protocol static static_bgp4 {
-    ipv4 {
-      table bgp4;
-    };
-    route 141.24.0.0/16 via ${config.networking.defaultGateway.address};
-  }
 
   protocol direct direct_lo {
     interface "lo";
@@ -148,30 +132,6 @@
     };
   }
 
-  protocol kernel kernel_bgp6 {
-    kernel table 2000;
-    ipv6 {
-      table bgp6;
-      export filter {
-        krt_prefsrc=${ (lib.head config.networking.interfaces.lo.ipv6.addresses).address };
-        accept;
-      };
-      import none;
-    };
-  }
-
-  protocol kernel kernel_bgp4 {
-    kernel table 2000;
-    ipv4 {
-      table bgp4;
-      export filter {
-        krt_prefsrc=${ (lib.head config.networking.interfaces.lo.ipv4.addresses).address };
-        accept;
-      };
-      import none;
-    };
-  }
-
   protocol ospf v3 ospf_6 {
     ipv6 {
       table ospf6;
@@ -200,50 +160,6 @@
     };
   }
 
-  template bgp ibgp6 {
-    local as 4200002574;
-    graceful restart on;
-    source address ${ (lib.head config.networking.interfaces.lo.ipv6.addresses).address };
-    ipv6 {
-      table bgp6;
-      igp table ospf6;
-      next hop self;
-      import keep filtered;
-      import all;
-      export all;
-    };
-  }
-
-  template bgp ibgp4 {
-    local as 4200002574;
-    graceful restart on;
-    source address ${ (lib.head config.networking.interfaces.lo.ipv4.addresses).address };
-    ipv4 {
-      table bgp4;
-      igp table ospf4;
-      next hop self;
-      import keep filtered;
-      import all;
-      export all;
-    };
-  }
-
-  protocol bgp bgp_carbon6 from ibgp6 {
-    neighbor fd00:152:152:104::1 as 4200002574;
-  }
-
-  protocol bgp bgp_carbon4 from ibgp4 {
-    neighbor 10.152.104.1 as 4200002574;
-  }
-
-  protocol bgp bgp_porter6 from ibgp6 {
-    neighbor fd00:152:152:102::1 as 4200002574;
-  }
-
-  protocol bgp bgp_porter4 from ibgp4 {
-    neighbor 10.152.102.1 as 4200002574;
-  }
-
   protocol device {
     scan time 10;
   }
diff --git a/hosts/porter/configuration.nix b/hosts/porter/configuration.nix
index bae6b0f..a454cc8 100644
--- a/hosts/porter/configuration.nix
+++ b/hosts/porter/configuration.nix
@@ -78,8 +78,6 @@
 
   ipv6 table ospf6;
   ipv4 table ospf4;
-  ipv6 table bgp6;
-  ipv4 table bgp4;
 
   protocol direct {
     interface "lo";
@@ -115,30 +113,6 @@
     };
   }
 
-  protocol kernel kernel_bgp6 {
-    kernel table 2000;
-    ipv6 {
-      table bgp6;
-      export filter {
-        krt_prefsrc=${ (lib.head config.networking.interfaces.lo.ipv6.addresses).address };
-        accept;
-      };
-      import none;
-    };
-  }
-
-  protocol kernel kernel_bgp4 {
-    kernel table 2000;
-    ipv4 {
-      table bgp4;
-      export filter {
-        krt_prefsrc=${ (lib.head config.networking.interfaces.lo.ipv4.addresses).address };
-        accept;
-      };
-      import none;
-    };
-  }
-
   protocol ospf v3 ospf_6 {
     ipv6 {
       table ospf6;
@@ -175,50 +149,6 @@
     };
   }
 
-  template bgp ibgp6 {
-    local as 4200002574;
-    graceful restart on;
-    source address ${ (lib.head config.networking.interfaces.lo.ipv6.addresses).address };
-    ipv6 {
-      table bgp6;
-      igp table ospf6;
-      next hop self;
-      import keep filtered;
-      import all;
-      export all;
-    };
-  }
-
-  template bgp ibgp4 {
-    local as 4200002574;
-    graceful restart on;
-    source address ${ (lib.head config.networking.interfaces.lo.ipv4.addresses).address };
-    ipv4 {
-      table bgp4;
-      igp table ospf4;
-      next hop self;
-      import keep filtered;
-      import all;
-      export all;
-    };
-  }
-
-  protocol bgp bgp_carbon6 from ibgp6 {
-    neighbor fd00:152:152:104::1 as 4200002574;
-  }
-
-  protocol bgp bgp_carbon4 from ibgp4 {
-    neighbor 10.152.104.1 as 4200002574;
-  }
-
-  protocol bgp bgp_nonat6 from ibgp6 {
-    neighbor fd00:152:152:103::1 as 4200002574;
-  }
-
-  protocol bgp bgp_nonat4 from ibgp4 {
-    neighbor 10.152.103.1 as 4200002574;
-  }
-
   protocol device {
     scan time 10;
   }
diff --git a/modules/gre-tunnel/default.nix b/modules/gre-tunnel/default.nix
new file mode 100644
index 0000000..c6c9d3b
--- /dev/null
+++ b/modules/gre-tunnel/default.nix
@@ -0,0 +1,52 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.clerie.gre-tunnel;
+
+  checkOpts = { config, ... }@moduleAttrs: {
+    options = {
+      remote = mkOption {
+        type = types.str;
+      };
+      local = mkOption {
+        type = types.str;
+      };
+      address = mkOption {
+        type = types.str;
+      };
+    };
+  };
+
+in {
+  options = {
+    clerie.gre-tunnel = {
+      enable = mkEnableOption "Declarative Policy-Routing";
+      ipv6 = mkOption {
+        type = with types; attrsOf (submodule checkOpts);
+      };
+      ipv4 = mkOption {
+        type = with types; attrsOf (submodule checkOpts);
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    clerie.gre-tunnel.rules = [
+      { rule = "lookup main"; prio = 32000; }
+    ];
+    networking.localCommands = ''
+      ${concatMapStringsSep "\n" ( mapAttrsToList ( name: tunnel: ''
+      ip -6 tunnel add ${name} mode gre remote ${tunnel.remote} local ${tunnel.local}
+      ip link set ${name} up
+      ip -6 a add ${tunnel.address} dev ${name}
+      '') cfg.ipv6 ) }
+      ${concatMapStringsSep "\n" ( mapAttrsToList ( name: tunnel: ''
+      ip -4 tunnel add ${name} mode gre remote ${tunnel.remote} local ${tunnel.local}
+      ip link set ${name} up
+      ip -4 a add ${tunnel.address} dev ${name}
+      '') cfg.ipv4 ) }
+    '';
+  };
+}