diff --git a/src/etc/inc/interfaces.inc b/src/etc/inc/interfaces.inc
index f73c8dd8f..f28dc2d4f 100644
--- a/src/etc/inc/interfaces.inc
+++ b/src/etc/inc/interfaces.inc
@@ -411,6 +411,10 @@ function _interfaces_lagg_configure($lagg)
 
     $interface_stats = legacy_interfaces_details();
     $members = explode(',', $lagg['members']);
+    if (!empty($lagg['primary_member'])) {
+        /* place primary member as first member */
+        $members = array_unique(array_merge([$lagg['primary_member']], $members));
+    }
 
     if (empty($interface_stats[$lagg['laggif']])) {
         legacy_interface_create($lagg['laggif']);
diff --git a/src/etc/inc/interfaces.lib.inc b/src/etc/inc/interfaces.lib.inc
index 0a165369d..e56bba260 100644
--- a/src/etc/inc/interfaces.lib.inc
+++ b/src/etc/inc/interfaces.lib.inc
@@ -416,13 +416,16 @@ function legacy_interfaces_details($intf = null)
             $result[$current_interface]['laggstatistics']['active ports'] = trim(explode(":", $next_line)[1]);
             $next_line = $ifconfig_data[$lineid + 2];
             $result[$current_interface]['laggstatistics']['flapping'] = trim(explode(":", $next_line)[1]);
-        } elseif (preg_match("/laggport: (.*)\Wflags=\d+<(.*)> state=\d+<(.*)>$/", $line, $matches)) {
+        } elseif (
+            preg_match("/laggport: (.*)\Wflags=\d+<(.*)> state=\d+<(.*)>$/", $line, $matches) ||
+            preg_match("/laggport: (.*)\Wflags=\d+<(.*)>.*/", $line, $matches)
+        ) {
             if (empty($result[$current_interface]['laggport'])) {
                 $result[$current_interface]['laggport'] = [];
             }
             $result[$current_interface]['laggport'][trim($matches[1])] = [
                 "flags" => explode(",", strtolower($matches[2])),
-                "state" => explode(",", strtolower($matches[3])),
+                "state" => isset($matches[3]) ? explode(",", strtolower($matches[3])) : [],
             ];
         } elseif (strpos($line, "\tgroups: ") !== false) {
             array_shift($line_parts);
diff --git a/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/forms/dialogLagg.xml b/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/forms/dialogLagg.xml
index 141f28f99..de90f954d 100644
--- a/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/forms/dialogLagg.xml
+++ b/src/opnsense/mvc/app/controllers/OPNsense/Interfaces/forms/dialogLagg.xml
@@ -17,6 +17,13 @@
         <type>dropdown</type>
         <help>The protocol to use, please refer to the documentation for a detailed explanation of the various types available</help>
     </field>
+    <field>
+        <id>lagg.primary_member</id>
+        <label>Primary interface</label>
+        <type>dropdown</type>
+        <style>selectpicker proto proto_failover</style>
+        <help>This interface will be added first in the lagg making it the primary one.</help>
+    </field>
     <field>
         <id>lagg.lacp_fast_timeout</id>
         <label>Fast timeout</label>
diff --git a/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.php b/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.php
index bd8e397dc..ea242b391 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.php
+++ b/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.php
@@ -55,28 +55,37 @@ class Lagg extends BaseModel
                 }
             }
         }
-        foreach ($this->getFlatNodes() as $key => $node) {
-            if ($validateFullModel || $node->isFieldChanged()) {
-                if ($node->getParentNode()->getInternalXMLTagName() === 'lagg') {
-                    $uuid = $node->getParentNode()->getAttributes()['uuid'];
-                    if ($node->getInternalXMLTagName() == 'members') {
-                        $tmp = [];
-                        foreach (explode(',', (string)$node) as $intf) {
-                            if (!empty($members[$intf]) && count($members[$intf]) > 1) {
-                                $tmp[] = $intf;
-                            }
-                        }
-                        if (!empty($tmp)) {
-                            $messages->appendMessage(
-                                new Message(
-                                    sprintf(gettext('Members %s are already used in other laggs.'), implode(',', $tmp)),
-                                    $key
-                                )
-                            );
-                        }
-                    }
+
+        foreach ($this->lagg->iterateItems() as $node) {
+            if (!$validateFullModel && !$node->isFieldChanged()) {
+                continue;
+            }
+            $uuid = $node->getAttributes()['uuid'];
+            $key = $node->__reference;
+            $members = explode(',', (string)$node->members);
+
+            $tmp = [];
+            foreach ($members as $intf) {
+                if (!empty($members[$intf]) && count($members[$intf]) > 1) {
+                    $tmp[] = $intf;
                 }
             }
+            if (!empty($tmp)) {
+                $messages->appendMessage(
+                    new Message(
+                        sprintf(gettext('Members %s are already used in other laggs.'), implode(',', $tmp)),
+                        $key . '.members'
+                    )
+                );
+            }
+            if (!empty((string)$node->primary_member) && !in_array((string)$node->primary_member, $members)) {
+                $messages->appendMessage(
+                    new Message(
+                        sprintf(gettext('Primary member %s not in member list.'), (string)$node->primary_member),
+                        $key . '.primary_member'
+                    )
+                );
+            }
         }
         return $messages;
     }
diff --git a/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.xml b/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.xml
index 251f86adb..5dce29295 100644
--- a/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.xml
+++ b/src/opnsense/mvc/app/models/OPNsense/Interfaces/Lagg.xml
@@ -19,6 +19,8 @@
                 <Multiple>Y</Multiple>
                 <ValidationMessage>At least one valid member is required</ValidationMessage>
             </members>
+            <primary_member type=".\LaggInterfaceField">
+            </primary_member>
             <proto type="OptionField">
               <Required>Y</Required>
               <Default>lacp</Default>