diff --git a/src/www/interfaces.php b/src/www/interfaces.php
index 4ec5efba2..94712f677 100644
--- a/src/www/interfaces.php
+++ b/src/www/interfaces.php
@@ -679,6 +679,15 @@ if ($_SERVER['REQUEST_METHOD'] === 'GET') {
                 }
                 break;
             case "6rd":
+                if (empty($pconfig['gateway-6rd']) || !is_ipaddrv4($pconfig['gateway-6rd'])) {
+                    $input_errors[] = gettext('6RD border relay gateway must be a valid IPv4 address.');
+                }
+                if (empty($pconfig['prefix-6rd']) || !is_subnetv6($pconfig['prefix-6rd'])) {
+                    $input_errors[] = gettext('6RD prefix must be a valid IPv6 subnet.');
+                }
+                if (!is_numeric($pconfig['prefix-6rd-v4plen'])) {
+                    $input_errors[] = gettext('6RD IPv4 prefix length must be a number.');
+                }
                 foreach ($ifdescrs as $ifent => $ifdescr) {
                     if ($if != $ifent && ($config[interfaces][$ifent]['ipaddrv6'] == $pconfig['type6'])) {
                         if ($config[interfaces][$ifent]['prefix-6rd'] == $pconfig['prefix-6rd']) {
diff --git a/src/www/interfaces_assign.php b/src/www/interfaces_assign.php
index f50d6affc..9cd6641a7 100644
--- a/src/www/interfaces_assign.php
+++ b/src/www/interfaces_assign.php
@@ -68,6 +68,9 @@ function list_interfaces() {
         if (match_wireless_interface($key)) {
             continue;
         }
+        if (preg_match('/_stf$/', $key)) {
+            continue;
+        }
         $interfaces[$key] = array('descr' => $key . ' (' . $intf_item['mac'] . ')', 'section' => 'interfaces');
     }
     // collect interfaces from defined config sections