diff --git a/bgpwtf/machines/modules/routing.nix b/bgpwtf/machines/modules/routing.nix
index 50f5ff8..ac222a9 100644
--- a/bgpwtf/machines/modules/routing.nix
+++ b/bgpwtf/machines/modules/routing.nix
@@ -140,6 +140,9 @@
                       default = false;
                       description = "Interface is stub (do not HELLO).";
                     };
+                    neighbors = mkOption {
+                      type = listOf str;
+                    };
                   };
                 });
                 description = "Interface configuration";
@@ -160,11 +163,18 @@
     ip = if v4 then "4" else "6";
     name = "ospf_${af}_${n}";
 
-    interfaces = mapAttrsToList (iface: ifaceConfig: ''
+    interfaces = mapAttrsToList (iface: ifaceConfig: let
+      neighbors = ''
+        neighbors {
+          ${concatStringsSep "\n" (map (n: "${n};") ifaceConfig.neighbors)}
+        };
+      '';
+    in ''
       interface "${iface}" {
         type ${ifaceConfig.type};
         cost ${toString ifaceConfig.cost};
         ${if ifaceConfig.stub then "stub yes;" else ""}
+        ${if ifaceConfig.type == "ptmp" then neighbors else ""}
       };
     '');
     areas = mapAttrsToList (area: areaConfig: ''