diff --git a/config/rootfiles/common/web-user-interface b/config/rootfiles/common/web-user-interface
index 44856fcc2..3eac4411a 100644
--- a/config/rootfiles/common/web-user-interface
+++ b/config/rootfiles/common/web-user-interface
@@ -308,6 +308,7 @@ srv/web/ipfire/html/images/wakeup.gif
 srv/web/ipfire/html/images/window-new.png
 srv/web/ipfire/html/include
 srv/web/ipfire/html/include/snortupdateutility.js
+srv/web/ipfire/html/include/zoneconf.js
 srv/web/ipfire/html/index.cgi
 srv/web/ipfire/html/redirect-templates
 srv/web/ipfire/html/redirect-templates/legacy
diff --git a/html/cgi-bin/zoneconf.cgi b/html/cgi-bin/zoneconf.cgi
index ef361af95..0914ceb78 100644
--- a/html/cgi-bin/zoneconf.cgi
+++ b/html/cgi-bin/zoneconf.cgi
@@ -26,7 +26,7 @@ require '/var/ipfire/general-functions.pl';
 require "${General::swroot}/lang.pl";
 require "${General::swroot}/header.pl";
 
-my $css = <<END
+my $extraHead = <<END
 <style>
 	table#zoneconf {
 		width: 100%;
@@ -101,6 +101,8 @@ my $css = <<END
 		margin-left: auto;
 	}
 </style>
+
+<script src="/include/zoneconf.js"></script>
 END
 ;
 
@@ -151,7 +153,7 @@ foreach (@nics) {
 	}
 }
 
-&Header::openpage($Lang::tr{"zoneconf title"}, 1, $css);
+&Header::openpage($Lang::tr{"zoneconf title"}, 1, $extraHead);
 &Header::openbigbox('100%', 'center');
 
 ### Evaluate POST parameters ###
@@ -364,6 +366,7 @@ foreach (@nics) {
 	foreach (@zones) {
 		my $uc = uc $_;
 		my $dev_name = $ethsettings{"${uc}_DEV"};
+		my $highlight = "";
 
 		if ($dev_name eq "") { # Again, skip the zone if it is not activated
 			next;
@@ -379,11 +382,12 @@ foreach (@nics) {
 
 				if ($mac eq $ethsettings{"${uc}_MACADDR"}) {
 					$checked = "checked";
+					$highlight = $_;
 				}
 
 				print <<END
-		<td class="">
-			<input type="radio" name="PPPACCESS" value="$mac" $checked>
+		<td class="$highlight">
+			<input type="radio" name="PPPACCESS" value="$mac" data-zone="RED" data-mac="$mac" onchange="highlightAccess(this)" $checked>
 		</td>
 END
 ;
@@ -424,9 +428,14 @@ END
 		$access_selected{"NONE"} = ($access_selected{"NATIVE"} eq "") && ($access_selected{"VLAN"} eq "") ? "selected" : "";
 		my $vlan_disabled = ($wlan) ? "disabled" : "";
 
+		# If the interface is assigned, hightlight table cell
+		if ($access_selected{"NONE"} eq "") {
+			$highlight = $_;
+		}
+
 		print <<END
-		<td class="">
-			<select name="ACCESS $uc $mac" onchange="document.getElementById('TAG-$uc-$mac').disabled = (this.value === 'VLAN' ? false : true)">
+		<td class="$highlight">
+			<select name="ACCESS $uc $mac" data-zone="$uc" data-mac="$mac" onchange="highlightAccess(this)">
 				<option value="NONE" $access_selected{"NONE"}>- $Lang::tr{"zoneconf access none"} -</option>
 				<option value="NATIVE" $access_selected{"NATIVE"}>$Lang::tr{"zoneconf access native"}</option>
 				<option value="VLAN" $access_selected{"VLAN"} $vlan_disabled>$Lang::tr{"zoneconf access vlan"}</option>
diff --git a/html/html/include/zoneconf.js b/html/html/include/zoneconf.js
new file mode 100644
index 000000000..d76f0ab68
--- /dev/null
+++ b/html/html/include/zoneconf.js
@@ -0,0 +1,56 @@
+/*#############################################################################
+#                                                                             #
+# IPFire.org - A linux based firewall                                         #
+# Copyright (C) 2007-2020  IPFire Team  <info@ipfire.org>                     #
+#                                                                             #
+# This program is free software: you can redistribute it and/or modify        #
+# it under the terms of the GNU General Public License as published by        #
+# the Free Software Foundation, either version 3 of the License, or           #
+# (at your option) any later version.                                         #
+#                                                                             #
+# This program is distributed in the hope that it will be useful,             #
+# but WITHOUT ANY WARRANTY; without even the implied warranty of              #
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the               #
+# GNU General Public License for more details.                                #
+#                                                                             #
+# You should have received a copy of the GNU General Public License           #
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.       #
+#                                                                             #
+#############################################################################*/
+
+//zoneconf.cgi dynamic highlighting of interface access selection
+//(call this from "onchange" event of selection elements)
+function highlightAccess(selectObj) {
+	if(!(selectObj && ('zone' in selectObj.dataset) && ('mac' in selectObj.dataset))) {
+		return; //required parameters are missing
+	}
+
+	var zoneColor = selectObj.dataset.zone.trim().toLowerCase(); //zone color (red/green/blue/orange) CSS class
+
+	function colorParentCell(obj, color, enabled = true) { //find nearest parent table cell of "obj" and set its CSS color class
+		do {
+			obj = obj.parentElement;
+		} while(obj && (obj.nodeName.toUpperCase() !== 'TD'));
+		if(obj && (['green', 'red', 'orange', 'blue'].includes(color))) {
+			obj.classList.toggle(color, enabled);
+		}
+	}
+
+	//handle other associated input fields
+	if(selectObj.type.toUpperCase() === 'RADIO') { //this is a radio button group: clear all highlights
+		let radios = document.getElementsByName(selectObj.name);
+		radios.forEach(function(button) {
+			if(button.nodeName.toUpperCase() === 'INPUT') { //make sure the found element is a button
+				colorParentCell(button, zoneColor, false); //remove css
+			}
+		});
+	} else { //this is a dropdown menu: enable/disable additional VLAN tag input box
+		let tagInput = document.getElementById('TAG-' + selectObj.dataset.zone + '-' + selectObj.dataset.mac); //tag input element selector
+		if(tagInput) {
+			tagInput.disabled = (selectObj.value !== 'VLAN'); //enable tag input if VLAN mode selected
+		}
+	}
+
+	//if interface is assigned, highlight table cell in zone color
+	colorParentCell(selectObj, zoneColor, (selectObj.value !== 'NONE'));
+}
