diff --git a/src/DhcpBundle/Controller/DhcpController.php b/src/DhcpBundle/Controller/DhcpController.php
index 5201251..a65e318 100644
--- a/src/DhcpBundle/Controller/DhcpController.php
+++ b/src/DhcpBundle/Controller/DhcpController.php
@@ -140,7 +140,7 @@ class DhcpController
             $output = shell_exec("df -h " . realpath($this->backup_dir) . " | tail -1 | awk '{print $2, $3, $4, $5}'");
             if (!$output) {
                 $this->logger->error("Failed to execute disk usage command");
-                return null;
+                return [];
             }
     
             list($total, $used, $available, $percentage) = explode(' ', $output);
@@ -217,6 +217,8 @@ class DhcpController
  *     @OA\Property(property="subnet", type="string", description="The name of the subnet"),
  *     @OA\Property(property="next-server", type="string", description="The next server in the subnet"),
  *     @OA\Property(property="boot-file-name", type="string", description="The boot file name for the subnet"),
+ *     @OA\Property(property="DNS", type="string", description="DNS subnet"),
+ *     @OA\Property(property="subnetName", type="string", description="subnetName subnet"),
  *     @OA\Property(
  *         property="reservations",
  *         type="array",
@@ -395,7 +397,7 @@ class DhcpController
  *             @OA\Property(property="mask", type="string", example="255.255.255.0"),
  *             @OA\Property(property="address", type="string", example="192.168.1.0"),
  *             @OA\Property(property="nextServer", type="string", example="192.168.1.1"),
- *             @OA\Property(property="subnetName", type="string", example="Aula informatica),
+ *             @OA\Property(property="subnetName", type="string", example="Aula informatica"),
  *             @OA\Property(property="DNS", type="string", example="192.168.1.1"),
  *             @OA\Property(property="bootFileName", type="string", example="pxelinux.0"),
  *             @OA\Property(property="router", type="string", example="192.168.1.254")
@@ -521,7 +523,7 @@ public function addDhcpSubnet(Request $request): JsonResponse
         if (!empty($DNS)) {
             $newSubnet["option-data"][] = [
                 "name" => "domain-name-servers",
-                "code" => 23,
+                "code" => 6,
                 "space" => "dhcp4",
                 "csv-format" => true,
                 "data" => $DNS
@@ -888,8 +890,8 @@ public function addDhcpSubnet(Request $request): JsonResponse
  *             type="object",
  *             @OA\Property(property="mask", type="string"),
  *             @OA\Property(property="address", type="string"),
- *             @OA\Property(property="DNS", type="string")
- *             @OA\Property(property="subnetName", type="string")
+ *             @OA\Property(property="DNS", type="string"),
+ *             @OA\Property(property="subnetName", type="string"),
  *             @OA\Property(property="router", type="string", example="192.168.1.254"),
  *             @OA\Property(property="nextServer", type="string"),
  *             @OA\Property(property="bootFileName", type="string")
@@ -2008,6 +2010,8 @@ public function updateDhcpHost(Request $request, $subnetId): JsonResponse
         ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES));
         return new JsonResponse(['error' => $errorText], Response::HTTP_INTERNAL_SERVER_ERROR);
     }
+
+    return new JsonResponse(['error' => 'Unexpected error occurred'], Response::HTTP_INTERNAL_SERVER_ERROR);
 }