diff --git a/machines/router03/router.nix b/machines/router03/router.nix
index 656bdd9..730f21d 100644
--- a/machines/router03/router.nix
+++ b/machines/router03/router.nix
@@ -4,10 +4,11 @@
     enable = true;
     enablePrimary = true;
     routerId = 1;
-    virtualRouterId = 1;
+    virtualRouterId = 51;
     vip = "129.199.146.230";
     rip = "129.199.146.231";
     trunkPort.macAddress = "92:E3:9C:CE:EF:14";
+    virtualNeighbors = [ 2 ];
   };
 
   # systemd.services."systemd-networkd".environment.SYSTEMD_LOG_LEVEL = "debug";
diff --git a/machines/router04/router.nix b/machines/router04/router.nix
index 5fce041..a1bb53a 100644
--- a/machines/router04/router.nix
+++ b/machines/router04/router.nix
@@ -4,10 +4,11 @@
     enable = true;
     enablePrimary = false;
     routerId = 2;
-    virtualRouterId = 1;
+    virtualRouterId = 51;
     vip = "129.199.146.230";
     rip = "129.199.146.232";
     trunkPort.macAddress = "92:E3:9C:CE:EF:15";
+    virtualNeighbors = [ 1 ];
   };
 
   # systemd.services."systemd-networkd".environment.SYSTEMD_LOG_LEVEL = "debug";
diff --git a/modules/krz-router.nix b/modules/krz-router.nix
index 85a3e78..7bc9794 100644
--- a/modules/krz-router.nix
+++ b/modules/krz-router.nix
@@ -56,6 +56,11 @@ in
       # As recommended per RFC.
       default = if cfg.enablePrimary then 100 else 50;
     };
+    virtualNeighbors = mkOption {
+      type = types.listOf types.int;
+      description = "Virtual router neighbors in terms of router IDs";
+      default = [ ];
+    };
   };
 
   config = mkIf cfg.enable {
@@ -353,6 +358,7 @@ in
         virtualIps = [{ addr = "${cfg.vip}/24"; dev = "swp"; scope = "global"; }];
         inherit (cfg) virtualRouterId;
         noPreempt = !cfg.enablePrimary;
+        unicastPeers = map (n: "10.0.0.${toString n}") cfg.virtualNeighbors;
       };
     };
   };