diff --git a/includes/discovery/fdb-table/vrp.inc.php b/includes/discovery/fdb-table/vrp.inc.php
index fcfa3224b6..f1166c404d 100644
--- a/includes/discovery/fdb-table/vrp.inc.php
+++ b/includes/discovery/fdb-table/vrp.inc.php
@@ -22,7 +22,10 @@ if (!empty($fdbPort_table)) {
     // Collect data and populate $insert
     foreach ($fdbPort_table as $mac => $data) {
         foreach ($data[$data_oid] as $vlan => $basePort) {
-            $ifIndex=$basePort[0];
+            $ifIndex=reset($basePort); // $baseport can be ['' => '119'] or ['0' => '119']
+            if (! $ifIndex) {
+                continue;
+            }
             $port = get_port_by_index_cache($device['device_id'], $ifIndex);
             $port_id = $port['port_id'];
             $mac_address = implode(array_map('zeropad', explode(':', $mac)));
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
index ca0cd6bcf7..cb3ea93ad5 100644
--- a/tests/bootstrap.php
+++ b/tests/bootstrap.php
@@ -44,7 +44,7 @@ ini_set('display_errors', 1);
 
 $snmpsim = new Snmpsim('127.1.6.2', 1162, null);
 if (getenv('SNMPSIM')) {
-    $snmpsim->fork();
+    $snmpsim->fork(6);
 
     // make PHP hold on a reference to $snmpsim so it doesn't get destructed
     register_shutdown_function(function (Snmpsim $ss) {