diff --git a/src/etc/inc/globals.inc b/src/etc/inc/globals.inc
index 9911f1cca7..6aba6653cd 100644
--- a/src/etc/inc/globals.inc
+++ b/src/etc/inc/globals.inc
@@ -32,6 +32,9 @@ define("IPV6", 6);
 define("IPV4V6", 2);
 define("ALIAS", 1);
 
+// Interface Name Size
+define("IF_NAMESIZE", 15);	/* 16 minus the terminating NULL */
+
 // AddPassword method defines
 define('DMYPWD', "********");
 
@@ -71,7 +74,7 @@ $g = array(
 	"disablecrashreporter" => false,
 	"crashreporterurl" => "https://crashreporter.pfsense.org/crash_reporter.php",
 	"debug" => false,
-	"latest_config" => "17.1",
+	"latest_config" => "17.2",
 	"minimum_ram_warning" => "101",
 	"minimum_ram_warning_text" => "128 MB",
 	"wan_interface_name" => "wan",
diff --git a/src/etc/inc/interfaces.inc b/src/etc/inc/interfaces.inc
index aad7d6ee31..7736e964e6 100644
--- a/src/etc/inc/interfaces.inc
+++ b/src/etc/inc/interfaces.inc
@@ -200,6 +200,91 @@ function interfaces_loopback_configure() {
 	return 0;
 }
 
+function vlan_valid_tag($tag = NULL) {
+
+	if ($tag == NULL || empty($tag) ||
+	    !is_numericint($tag) || intval($tag) < 1 || intval($tag) > 4094) {
+		return (false);
+	}
+	return (true);
+}
+
+function qinq_inuse($qinq = NULL, $inqtag = NULL) {
+        global $config;
+  
+	if ($qinq == NULL || $inqtag == NULL ||
+	    !is_array($qinq) || !vlan_valid_tag($inqtag)) {
+		return (false);
+	}
+ 
+        $iflist = get_configured_interface_list(true);
+        foreach ($iflist as $if) {
+                if ($config['interfaces'][$if]['if'] == qinq_interface($qinq, $inqtag)) {
+                        return (true);
+                }
+        }
+       
+        return (false);
+}      
+
+function qinq_interface($qinq = NULL, $inqtag = NULL) {
+
+	if ($qinq == NULL || $inqtag == NULL || !is_array($qinq) ||
+	    !isset($qinq['if']) || !isset($qinq['tag']) ||
+	    !vlan_valid_tag($qinq['tag']) || !vlan_valid_tag($inqtag)) {
+		return (NULL);
+	}
+	return ("{$qinq['if']}.{$qinq['tag']}.{$inqtag}");
+}
+
+function interface_is_qinq($if = NULL) {
+	global $config;
+
+	if ($if == NULL || empty($if) || !is_array($config['qinqs']['qinqentry'])) {
+		return (NULL);
+	}
+
+	/* Check basic format. */
+	list($qinqif, $vlantag, $inqtag) = explode(".", $if);
+	if (empty($qinqif) || empty($vlantag) || empty($inqtag) ||
+	    !vlan_valid_tag($vlantag) || !vlan_valid_tag($inqtag)) {
+		return (NULL);
+	}
+
+	foreach ($config['qinqs']['qinqentry'] as $qinqidx => $qinq) {
+		if ("{$qinqif}.{$vlantag}" != $qinq['vlanif']) {
+			continue;
+		}
+		if (empty($qinq['members'])) {
+			continue;
+		}
+		foreach (explode(" ", $qinq['members']) as $tag) {
+			if ($if == qinq_interface($qinq, $tag)) {
+				return ($qinq);
+			}
+		}
+	}
+
+	return (NULL);
+}
+
+function vlan_inuse($vlan) {
+	global $config;
+
+	if ($vlan == NULL || !is_array($vlan)) {
+		return (false);
+	}
+
+	$iflist = get_configured_interface_list(true);
+	foreach ($iflist as $if) {
+		if ($config['interfaces'][$if]['if'] == $vlan['vlanif']) {
+			return (true);
+		}
+	}
+
+	return (false);
+}
+
 function interface_is_vlan($if = NULL) {
 	global $config;
 
@@ -227,7 +312,8 @@ function interface_is_vlan($if = NULL) {
 function vlan_interface($vlan = NULL) {
 
 	if ($vlan == NULL || !is_array($vlan) ||
-	    !isset($vlan['if']) || !isset($vlan['tag'])) {
+	    !isset($vlan['if']) || !isset($vlan['tag']) ||
+	    intval($vlan['tag']) < 0 || intval($vlan['tag']) > 4094) {
 		return (NULL);
 	}
 	return ("{$vlan['if']}.{$vlan['tag']}");
@@ -311,16 +397,16 @@ function interface_vlan_configure(&$vlan) {
 	return $vlanif;
 }
 
-function interface_qinq_configure(&$vlan, $fd = NULL) {
+function interface_qinq_configure(&$qinq, $fd = NULL) {
 	global $config, $g;
 
-	if (!is_array($vlan)) {
+	if (!is_array($qinq)) {
 		log_error(sprintf(gettext("QinQ compat VLAN: called with wrong options. Problems with config!%s"), "\n"));
 		return;
 	}
 
-	$qinqif = $vlan['if'];
-	$tag = $vlan['tag'];
+	$qinqif = $qinq['if'];
+	$tag = $qinq['tag'];
 	if (empty($qinqif)) {
 		log_error(sprintf(gettext("interface_qinq_configure called with if undefined.%s"), "\n"));
 		return;
@@ -331,8 +417,8 @@ function interface_qinq_configure(&$vlan, $fd = NULL) {
 		return;
 	}
 
-	$vlanif = interface_vlan_configure($vlan);
-	if ($vlanif == NULL) {
+	$vlanif = interface_vlan_configure($qinq);
+	if ($vlanif == NULL || $vlanif != $qinq['vlanif']) {
 		log_error(gettext("interface_qinq_configure cannot create VLAN interface"));
 		return;
 	}
@@ -347,47 +433,53 @@ function interface_qinq_configure(&$vlan, $fd = NULL) {
 	interfaces_bring_up($qinqif);
 
 	pfSense_ngctl_attach(".", $qinqif);
+	$ngif = str_replace(".", "_", $vlanif);
 	if (!empty($vlanif) && does_interface_exist($vlanif)) {
-		fwrite($fd, "shutdown {$vlanif}qinq:\n");
-		exec("/usr/sbin/ngctl msg {$vlanif}qinq: gettable", $result);
+		exec("/usr/sbin/ngctl shutdown {$ngif}qinq: > /dev/null 2>&1");
+		exec("/usr/sbin/ngctl msg {$ngif}qinq: gettable > /dev/null 2>&1", $result);
 		if (empty($result)) {
-			fwrite($fd, "mkpeer {$vlanif}: vlan lower downstream\n");
-			fwrite($fd, "name {$vlanif}:lower {$vlanif}qinq\n");
-			fwrite($fd, "connect {$vlanif}: {$vlanif}qinq: upper nomatch\n");
+			fwrite($fd, "mkpeer {$ngif}: vlan lower downstream\n");
+			fwrite($fd, "name {$ngif}:lower {$ngif}qinq\n");
+			fwrite($fd, "connect {$ngif}: {$ngif}qinq: upper nomatch\n");
 		}
 	} else {
-		fwrite($fd, "mkpeer {$vlanif}: vlan lower downstream\n");
-		fwrite($fd, "name {$vlanif}:lower {$vlanif}qinq\n");
-		fwrite($fd, "connect {$vlanif}: {$vlanif}qinq: upper nomatch\n");
+		fwrite($fd, "mkpeer {$ngif}: vlan lower downstream\n");
+		fwrite($fd, "name {$ngif}:lower {$ngif}qinq\n");
+		fwrite($fd, "connect {$ngif}: {$ngif}qinq: upper nomatch\n");
 	}
 
 	/* invalidate interface cache */
 	get_interface_arr(true);
 
-	if (!stristr($qinqif, "_vlan")) {
+	if (interface_is_vlan($qinqif) == NULL) {
 		mwexec("/sbin/ifconfig {$qinqif} promisc\n");
 	}
 
 	$macaddr = get_interface_mac($qinqif);
-	if (!empty($vlan['members'])) {
-		$members = explode(" ", $vlan['members']);
+	if (!empty($qinq['members'])) {
+		$qinqcmdbuf = "";
+		$members = explode(" ", $qinq['members']);
 		foreach ($members as $qtag) {
-			$qinq = array();
-			$qinq['tag'] = $qtag;
-			$qinq['if'] = $vlanif;
-			interface_qinq2_configure($qinq, $fd, $macaddr);
+			$qinq2 = array();
+			$qinq2['tag'] = $qtag;
+			$qinq2['if'] = $vlanif;
+			interface_qinq2_configure($qinq2, $qinqcmdbuf, $macaddr);
+			unset($qinq2);
+		}
+		if (strlen($qinqcmdbuf) > 0) {
+			fwrite($fd, $qinqcmdbuf);
 		}
 	}
 	if ($exec == true) {
 		fclose($fd);
-		mwexec("/usr/sbin/ngctl -f {$g['tmp_path']}/netgraphcmd");
+		mwexec("/usr/sbin/ngctl -f {$g['tmp_path']}/netgraphcmd > /dev/null 2>&1");
 	}
 
 	interfaces_bring_up($qinqif);
-	if (!empty($vlan['members'])) {
-		$members = explode(" ", $vlan['members']);
-		foreach ($members as $qif) {
-			interfaces_bring_up("{$vlanif}_{$qif}");
+	if (!empty($qinq['members'])) {
+		$members = explode(" ", $qinq['members']);
+		foreach ($members as $qtag) {
+			interfaces_bring_up(qinq_interface($qinq, $qtag));
 		}
 	}
 
@@ -410,7 +502,7 @@ function interfaces_qinq_configure() {
 	}
 }
 
-function interface_qinq2_configure(&$qinq, $fd, $macaddr) {
+function interface_qinq2_configure(&$qinq, &$cmdbuf, $macaddr) {
 	global $config, $g;
 
 	if (!is_array($qinq)) {
@@ -419,19 +511,25 @@ function interface_qinq2_configure(&$qinq, $fd, $macaddr) {
 	}
 
 	$if = $qinq['if'];
-	$tag = $qinq['tag'];
-	$vlanif = "{$if}_{$tag}";
 	if (empty($if)) {
 		log_error(sprintf(gettext("interface_qinq2_configure called with if undefined.%s"), "\n"));
 		return;
 	}
+	$tag = $qinq['tag'];
+	$vlanif = "{$if}.{$tag}";
+	$ngif = str_replace(".", "_", $if);
+	if (strlen($vlanif) > IF_NAMESIZE) {
+		log_error(sprintf(gettext("interface_qinq2_configure interface name too big %s. (max. size: %d).%s"),
+		    $vlanif, IF_NAMESIZE, "\n"));
+		return;
+	}
 
-	fwrite($fd, "shutdown {$if}h{$tag}:\n");
-	fwrite($fd, "mkpeer {$if}qinq: eiface {$if}{$tag} ether\n");
-	fwrite($fd, "name {$if}qinq:{$if}{$tag} {$if}h{$tag}\n");
-	fwrite($fd, "msg {$if}qinq: addfilter { vlan={$tag} hook=\"{$if}{$tag}\" }\n");
-	fwrite($fd, "msg {$if}h{$tag}: setifname \"{$vlanif}\"\n");
-	fwrite($fd, "msg {$if}h{$tag}: set {$macaddr}\n");
+	exec("/usr/sbin/ngctl shutdown {$ngif}h{$tag}: > /dev/null 2>&1");
+	$cmdbuf .= "mkpeer {$ngif}qinq: eiface {$ngif}{$tag} ether\n";
+	$cmdbuf .= "name {$ngif}qinq:{$ngif}{$tag} {$ngif}h{$tag}\n";
+	$cmdbuf .= "msg {$ngif}qinq: addfilter { vlan={$tag} hook=\"{$ngif}{$tag}\" }\n";
+	$cmdbuf .= "msg {$ngif}h{$tag}: setifname \"{$vlanif}\"\n";
+	$cmdbuf .= "msg {$ngif}h{$tag}: set {$macaddr}\n";
 
 	/* invalidate interface cache */
 	get_interface_arr(true);
diff --git a/src/etc/inc/upgrade_config.inc b/src/etc/inc/upgrade_config.inc
index 1eeb4ce795..6983a4d85a 100644
--- a/src/etc/inc/upgrade_config.inc
+++ b/src/etc/inc/upgrade_config.inc
@@ -5442,6 +5442,35 @@ function upgrade_170_to_171() {
 	}
 }
 
+/* Upgrade the QinQ interface names to use $if.$tag instead of $if_$tag.
+ * This helps keep the interface names smaller than the limit (but they are still
+ * big with the QinQ subtag).
+ */
+function upgrade_171_to_172() {
+	global $config;
+
+	if (!is_array($config['qinqs']['qinqentry']) || count($config['qinqs']['qinqentry']) == 0) {
+		return;
+	}
+	$iflist = get_configured_interface_list(true);
+	foreach ($config['qinqs']['qinqentry'] as $id => $qinq) {
+		$config['qinqs']['qinqentry'][$id]['vlanif'] = vlan_interface($qinq);
+
+		if (!isset($qinq['members'])) {
+			continue;
+		}
+		foreach (explode(" ", $qinq['members']) as $tag) {
+			/* Make sure to update the interfaces section with the new name. */
+			$vlan_name = "{$qinq['if']}_{$qinq['tag']}_{$tag}";
+			foreach ($iflist as $ifname) {
+				if ($config['interfaces'][$ifname]['if'] == $vlan_name) {
+					$config['interfaces'][$ifname]['if'] = qinq_interface($qinq, $tag);
+				}
+			}
+		}
+	}
+}
+
 /*
  * Special function that is called independent of current config version. It's
  * a workaround to have config_upgrade running on older versions after next
diff --git a/src/etc/inc/util.inc b/src/etc/inc/util.inc
index ef39ebf592..12cedb5f9d 100644
--- a/src/etc/inc/util.inc
+++ b/src/etc/inc/util.inc
@@ -2154,6 +2154,7 @@ function is_interface_mismatch() {
 	if (is_array($config['interfaces'])) {
 		foreach ($config['interfaces'] as $ifname => $ifcfg) {
 			if (interface_is_vlan($ifcfg['if']) != NULL ||
+			    interface_is_qinq($ifcfg['if']) != NULL ||
 			    preg_match("/^enc|^cua|^tun|^tap|^l2tp|^pptp|^ppp|^ovpn|^gif|^gre|^lagg|^bridge|vlan|_wlan|_\d{0,4}_\d{0,4}$/i", $ifcfg['if'])) {
 				// Do not check these interfaces.
 				$i++;
diff --git a/src/usr/local/www/interfaces_assign.php b/src/usr/local/www/interfaces_assign.php
index f949df9439..79d11e398a 100644
--- a/src/usr/local/www/interfaces_assign.php
+++ b/src/usr/local/www/interfaces_assign.php
@@ -163,8 +163,8 @@ if (is_array($config['qinqs']['qinqentry']) && count($config['qinqs']['qinqentry
 		/* QinQ members */
 		$qinqifs = explode(' ', $qinq['members']);
 		foreach ($qinqifs as $qinqif) {
-			$portlist["{$qinq['vlanif']}_{$qinqif}"]['descr'] = "QinQ {$qinqif} on VLAN {$qinq['tag']} on {$qinq['if']}";
-			$portlist["{$qinq['vlanif']}_{$qinqif}"]['isqinq'] = true;
+			$portlist["{$qinq['vlanif']}.{$qinqif}"]['descr'] = "QinQ {$qinqif} on VLAN {$qinq['tag']} on {$qinq['if']}";
+			$portlist["{$qinq['vlanif']}.{$qinqif}"]['isqinq'] = true;
 		}
 	}
 }
diff --git a/src/usr/local/www/interfaces_qinq.php b/src/usr/local/www/interfaces_qinq.php
index 3fff40bb5f..b2081983bd 100644
--- a/src/usr/local/www/interfaces_qinq.php
+++ b/src/usr/local/www/interfaces_qinq.php
@@ -35,24 +35,11 @@ if (!is_array($config['qinqs']['qinqentry'])) {
 
 $a_qinqs = &$config['qinqs']['qinqentry'];
 
-function qinq_inuse($num) {
-	global $config, $a_qinqs;
-
-	$iflist = get_configured_interface_list(true);
-	foreach ($iflist as $if) {
-		if ($config['interfaces'][$if]['if'] == $a_qinqs[$num]['qinqif']) {
-			return true;
-		}
-	}
-
-	return false;
-}
-
 if ($_POST['act'] == "del") {
 	$id = $_POST['id'];
 
 	/* check if still in use */
-	if (qinq_inuse($id)) {
+	if (isset($a_qinqs) && vlan_inuse($a_qinqs[$id])) {
 		$input_errors[] = gettext("This QinQ cannot be deleted because it is still being used as an interface.");
 	} elseif (empty($a_qinqs[$id]['vlanif']) || !does_interface_exist($a_qinqs[$id]['vlanif'])) {
 		$input_errors[] = gettext("QinQ interface does not exist");
@@ -60,13 +47,24 @@ if ($_POST['act'] == "del") {
 		$qinq =& $a_qinqs[$id];
 
 		$delmembers = explode(" ", $qinq['members']);
-		if (count($delmembers) > 0) {
-			foreach ($delmembers as $tag) {
-				mwexec("/usr/sbin/ngctl shutdown {$qinq['vlanif']}h{$tag}:");
+		foreach ($delmembers as $tag) {
+			if (qinq_inuse($qinq, $tag)) {
+				$input_errors[] = gettext("This QinQ cannot be deleted because one of it tags is still being used as an interface.");
+				break;
 			}
 		}
-		mwexec("/usr/sbin/ngctl shutdown {$qinq['vlanif']}qinq:");
-		mwexec("/usr/sbin/ngctl shutdown {$qinq['vlanif']}:");
+	}
+
+	if (empty($input_errors)) {
+		$qinq =& $a_qinqs[$id];
+
+		$ngif = str_replace(".", "_", $qinq['vlanif']);
+		$delmembers = explode(" ", $qinq['members']);
+		foreach ($delmembers as $tag) {
+			mwexec("/usr/sbin/ngctl shutdown {$ngif}h{$tag}:  > /dev/null 2>&1");
+		}
+		mwexec("/usr/sbin/ngctl shutdown {$ngif}qinq: > /dev/null 2>&1");
+		mwexec("/usr/sbin/ngctl shutdown {$ngif}: > /dev/null 2>&1");
 		pfSense_interface_destroy($qinq['vlanif']);
 		unset($a_qinqs[$id]);
 
diff --git a/src/usr/local/www/interfaces_qinq_edit.php b/src/usr/local/www/interfaces_qinq_edit.php
index e75d02b692..95fa3c974e 100644
--- a/src/usr/local/www/interfaces_qinq_edit.php
+++ b/src/usr/local/www/interfaces_qinq_edit.php
@@ -143,10 +143,22 @@ if ($_POST['save']) {
 		$input_errors[] = gettext("At least one tag must be entered.");
 	}
 
+	$nmembers = explode(" ", $members);
+	if (isset($id) && $a_qinqs[$id]) {
+		$omembers = explode(" ", $a_qinqs[$id]['members']);
+		$delmembers = array_diff($omembers, $nmembers);
+		foreach ($delmembers as $tag) {
+			if (qinq_inuse($a_qinqs[$id], $tag)) {
+				$input_errors[] = gettext("This QinQ tag cannot be deleted because it is still being used as an interface.");
+				break;
+			}
+		}
+	}
+
 	if (!$input_errors) {
 		$qinqentry['members'] = $members;
 		$qinqentry['descr'] = $_POST['descr'];
-		$qinqentry['vlanif'] = "{$_POST['if']}_{$_POST['tag']}";
+		$qinqentry['vlanif'] = vlan_interface($_POST);
 		$nmembers = explode(" ", $members);
 
 		if (isset($id) && $a_qinqs[$id]) {
@@ -155,22 +167,29 @@ if ($_POST['save']) {
 			$addmembers = array_diff($nmembers, $omembers);
 
 			if ((count($delmembers) > 0) || (count($addmembers) > 0)) {
-				$fd = fopen("{$g['tmp_path']}/netgraphcmd", "w");
 				foreach ($delmembers as $tag) {
-					fwrite($fd, "shutdown {$qinqentry['vlanif']}h{$tag}:\n");
-					fwrite($fd, "msg {$qinqentry['vlanif']}qinq: delfilter \\\"{$qinqentry['vlanif']}{$tag}\\\"\n");
+					$ngif = str_replace(".", "_", $qinqentry['vlanif']);
+					exec("/usr/sbin/ngctl shutdown {$ngif}h{$tag}: > /dev/null 2>&1");
+					exec("/usr/sbin/ngctl msg {$ngif}qinq: delfilter \\\"{$ngif}{$tag}\\\" > /dev/null 2>&1");
 				}
 
+				$qinqcmdbuf = "";
 				foreach ($addmembers as $member) {
 					$qinq = array();
 					$qinq['if'] = $qinqentry['vlanif'];
 					$qinq['tag'] = $member;
 					$macaddr = get_interface_mac($qinqentry['vlanif']);
-					interface_qinq2_configure($qinq, $fd, $macaddr);
+					interface_qinq2_configure($qinq, $qinqcmdbuf, $macaddr);
 				}
 
-				fclose($fd);
-				mwexec("/usr/sbin/ngctl -f {$g['tmp_path']}/netgraphcmd");
+				if (strlen($qinqcmdbuf) > 0) {
+					$fd = fopen("{$g['tmp_path']}/netgraphcmd", "w");
+					if ($fd) {
+						fwrite($fd, $qinqcmdbuf);
+						fclose($fd);
+						mwexec("/usr/sbin/ngctl -f {$g['tmp_path']}/netgraphcmd > /dev/null 2>&1");
+					}
+				}
 			}
 			$a_qinqs[$id] = $qinqentry;
 		} else {
@@ -189,7 +208,7 @@ if ($_POST['save']) {
 			}
 			$additions = "";
 			foreach ($nmembers as $qtag) {
-				$additions .= "{$qinqentry['vlanif']}_{$qtag} ";
+				$additions .= qinq_interface($qinqentry, $qtag) . " ";
 			}
 			$additions .= "{$qinqentry['vlanif']}";
 			if ($found == true) {
diff --git a/src/usr/local/www/interfaces_vlan.php b/src/usr/local/www/interfaces_vlan.php
index d944616e4f..6510e3abae 100644
--- a/src/usr/local/www/interfaces_vlan.php
+++ b/src/usr/local/www/interfaces_vlan.php
@@ -38,26 +38,13 @@ if (!is_array($config['vlans']['vlan'])) {
 
 $a_vlans = &$config['vlans']['vlan'] ;
 
-function vlan_inuse($num) {
-	global $config, $a_vlans;
-
-	$iflist = get_configured_interface_list(true);
-	foreach ($iflist as $if) {
-		if ($config['interfaces'][$if]['if'] == $a_vlans[$num]['vlanif']) {
-			return true;
-		}
-	}
-
-	return false;
-}
-
 if ($_POST['act'] == "del") {
 	if (!isset($_POST['id'])) {
 		$input_errors[] = gettext("Wrong parameters supplied");
 	} else if (empty($a_vlans[$_POST['id']])) {
 		$input_errors[] = gettext("Wrong index supplied");
 	/* check if still in use */
-	} else if (vlan_inuse($_POST['id'])) {
+	} else if (vlan_inuse($a_vlans[$_POST['id']])) {
 		$input_errors[] = gettext("This VLAN cannot be deleted because it is still being used as an interface.");
 	} else {
 		if (does_interface_exist($a_vlans[$_POST['id']]['vlanif'])) {