diff --git a/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/Api/VipSettingsController.php b/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/Api/VipSettingsController.php
index 553176c1c..6e2fb5f3f 100644
--- a/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/Api/VipSettingsController.php
+++ b/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/Api/VipSettingsController.php
@@ -43,12 +43,12 @@ class VipSettingsController extends ApiMutableModelControllerBase
      */
     private function getVipOverlay()
     {
-        $overlay = ['network' => ''];
+        $overlay = ['network' => '', 'subnet' => '', 'subnet_bits' => ''];
         $tmp = $this->request->getPost('vip');
         if (!empty($tmp['network'])) {
             $parts = explode('/', $tmp['network'], 2);
             $overlay['subnet'] = $parts[0];
-            if (count($parts) < 2) {
+            if (count($parts) == 1 || $parts[1] == '') {
                 $overlay['subnet_bits'] = strpos($parts[0], ':') !== false ? 128 : 32;
             } else {
                 $overlay['subnet_bits'] = $parts[1];
diff --git a/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/VipNetworkField.php b/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/VipNetworkField.php
index 52e62b095..b31ce69bb 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/VipNetworkField.php
+++ b/src/opnsense/mvc/app/models/OPNsense/Interfaces/FieldTypes/VipNetworkField.php
@@ -45,15 +45,12 @@ class VipNetworkField extends TextField
         }
         $validators[] = new CallbackValidator(["callback" => function ($data) {
             $parent = $this->getParentNode();
-            $subnet_bits = (string)$parent->subnet_bits;
-            $subnet = (string)$parent->subnet;
             $messages = [];
-            if (!Util::isSubnet($subnet . "/" . $subnet_bits)) {
-                $messages[] = sprintf(
-                    gettext('Entry "%s/%s" is not a valid network address.'),
-                    $subnet,
-                    $subnet_bits
-                );
+            $network = implode('/', [(string)$parent->subnet, (string)$parent->subnet_bits]);
+            if (empty((string)$parent->subnet)) {
+                $messages[] = gettext('A network address is required.');
+            } elseif (!Util::isIpAddress((string)$parent->subnet) || !Util::isSubnet($network)) {
+                $messages[] = sprintf(gettext('Entry "%s" is not a valid network address.'), $network);
             }
             return $messages;
         }
diff --git a/src/opnsense/mvc/app/models/OPNsense/Interfaces/Vip.php b/src/opnsense/mvc/app/models/OPNsense/Interfaces/Vip.php
index eb6a9bbd4..1aca7dc8b 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Interfaces/Vip.php
+++ b/src/opnsense/mvc/app/models/OPNsense/Interfaces/Vip.php
@@ -44,7 +44,7 @@ class Vip extends BaseModel
         $vips = [];
         $carp_vhids = [];
 
-        // collect chaned VIP entries
+        // collect changed VIP entries
         $vip_fields = ['mode', 'subnet', 'subnet_bits', 'password', 'vhid', 'interface'];
         foreach ($this->getFlatNodes() as $key => $node) {
             $tagName = $node->getInternalXMLTagName();