diff --git a/ajax/networking/save_net_dev_config.php b/ajax/networking/save_net_dev_config.php
index e90cd1ea..57c4c30f 100644
--- a/ajax/networking/save_net_dev_config.php
+++ b/ajax/networking/save_net_dev_config.php
@@ -39,7 +39,9 @@ if (isset($_POST['interface'])) {
             $pid=$_POST["int-pid-".$dev];
             $mac=$_POST["int-mac-".$dev];
             $name=trim($_POST["int-name-".$dev]);
+			// limit device name to letters and numbers. Total length max 20
             $name=preg_replace("/[^a-z0-9]/", "", strtolower($name));
+            $name=substr($name, 0, min(strlen($name),20));
             $type=$_POST["int-type-".$dev];
             $newtype=$_POST["int-new-type-".$dev];
             $udevfile=$_SESSION["udevrules"]["udev_rules_file"]; // default file /etc/udev/rules.d/80-net-devices.rules";
@@ -72,7 +74,6 @@ if (isset($_POST['interface'])) {
                 if (!empty($name)) $rule = preg_replace("/\\\$DEVNAME\\\$/i",$name,$rule);
                 if (!empty($rule)) exec('echo \''.$rule.'\' | sudo /usr/bin/tee -a '.$udevfile);
             }
-            $ret=print_r($ret,true);
             $jsonData = ['return'=>0,'output'=>['Settings changed for device '.$dev. '<br>Changes will only be in effect after reconnecting the device'  ] ];
             echo json_encode($jsonData);
             return;
diff --git a/config/client_udev_prototypes.json b/config/client_udev_prototypes.json
index 2cca8257..a147e776 100644
--- a/config/client_udev_prototypes.json
+++ b/config/client_udev_prototypes.json
@@ -9,7 +9,7 @@
      "clientid": 0,
      "comment": "standard ethernet port",
      "name_prefix": "eth",
-     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", ATTR{address}==\"$MAC$\", NAME=\"$DEVNAME$\", ENV{raspapType}="eth" "
+     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", ATTR{address}==\"$MAC$\", NAME=\"$DEVNAME$\", ENV{raspapType}=\"eth\" "
     },
     {
      "type": "usb", 
@@ -17,7 +17,7 @@
      "clientid": 1,
      "comment": "network interface - e.g. USB tethering of an Android phone ",
      "name_prefix": "usb",
-     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", SUBSYSTEMS==\"usb\", ATTRS{idVendor}==\"$IDVENDOR$\", ATTRS{idProduct}==\"$IDPRODUCT$\", NAME=\"$DEVNAME$\", ENV{raspapType}="eth"  "
+     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", SUBSYSTEMS==\"usb\", ATTRS{idVendor}==\"$IDVENDOR$\", ATTRS{idProduct}==\"$IDPRODUCT$\", NAME=\"$DEVNAME$\", ENV{raspapType}=\"eth\" "
     },
     {
      "type": "wlan", 
@@ -25,7 +25,7 @@
      "clientid": 2,
      "comment": "standard wireless interface",
      "name_prefix": "wlan",
-     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", ATTR{address}==\"$MAC$\", NAME=\"$DEVNAME$\", ENV{raspapType}="wlan"  "
+     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", ATTR{address}==\"$MAC$\", NAME=\"$DEVNAME$\", ENV{raspapType}=\"wlan\" "
     },
     {
      "type": "ppp", 
@@ -42,7 +42,7 @@
      "comment": "Huawei mobile data device in router mode. Control via HTTP",
      "name_prefix": "hilink",
      "default_ip": "192.168.8.1",
-     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", SUBSYSTEMS==\"usb\", ATTRS{idVendor}==\"$IDVENDOR$\", ATTRS{idProduct}==\"$IDPRODUCT$\", NAME=\"$DEVNAME$\", ENV{raspapType}="hilink",  TAG+=\"systemd\", ENV{SYSTEMD_WANTS}=\"start start_huawei_hilink.service\" "
+     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", SUBSYSTEMS==\"usb\", ATTRS{idVendor}==\"$IDVENDOR$\", ATTRS{idProduct}==\"$IDPRODUCT$\", NAME=\"$DEVNAME$\", ENV{raspapType}=\"hilink\", TAG+=\"systemd\", ENV{SYSTEMD_WANTS}=\"start start_huawei_hilink.service\" "
     },
     {
      "type": "phone", 
@@ -50,14 +50,14 @@
      "clientid": 5,
      "comment": "ethernet access provided by tethering from phone via USB",
      "name_prefix": "phone",
-     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", SUBSYSTEMS==\"usb\", ATTRS{idVendor}==\"$IDVENDOR$\", ATTRS{idProduct}==\"$IDPRODUCT$\", NAME=\"$DEVNAME$\", ENV{raspapType}="phone"  "
+     "udev_rule": "SUBSYSTEM==\"net\", ACTION==\"add\", SUBSYSTEMS==\"usb\", ATTRS{idVendor}==\"$IDVENDOR$\", ATTRS{idProduct}==\"$IDPRODUCT$\", NAME=\"$DEVNAME$\", ENV{raspapType}=\"phone\" "
     },
-	{
+    {
      "type": "tun", 
      "type_info": "tunnel device", 
      "clientid": -1,
      "comment": "tunneling device used by OpenVPN",
-     "name_prefix": "tun",
+     "name_prefix": "tun"
     }
   ]
 }