diff --git a/lang/en/admin.php b/lang/en/admin.php
index aa79e8e6f78..0103646de7e 100644
--- a/lang/en/admin.php
+++ b/lang/en/admin.php
@@ -631,7 +631,7 @@ $string['invalidsection'] = 'Invalid section.';
 $string['invaliduserchangeme'] = 'Username "changeme" is reserved -- you cannot create an account with it.';
 $string['ipblocked'] = 'This site is not available currently.';
 $string['ipblocker'] = 'IP blocker';
-$string['ipblockersyntax'] = 'Put every entry on one line. Valid entries are either full IP address (such as <b>192.168.10.1</b>) which matches a single host; or partial address (such as <b>192.168</b>) which matches any address starting with those numbers; or CIDR notation (such as <b>231.54.211.0/20</b>); or a range of IP addresses (such as <b>231.3.56.10-20</b>) where the range applies to the last part of the address. Text domain names (like \'example.com\') are not supported. Blank lines are ignored.';
+$string['ipblockersyntax'] = 'Put every entry on one line. Valid entries are either full IP address (such as <b>192.168.10.1</b>) which matches a single host; or partial address (such as <b>192.168</b>) which matches any address starting with those numbers; or CIDR notation (such as <b>231.54.211.0/20</b>); or a range of IP addresses (such as <b>231.3.56.10-20</b>) where the range applies to the last part of the address. Text domain names (like \'example.com\') are not supported. Blank lines, and text following a "#" character are ignored.';
 $string['iplookup'] = 'IP address lookup';
 $string['iplookupgeoplugin'] = '<a href="http://www.geoplugin.com">geoPlugin</a> service is currently being used to look up geographical information. For more accurate results we recommend installing a local copy of the MaxMind GeoLite database.';
 $string['iplookupinfo'] = 'By default Moodle uses the free online NetGeo (The Internet Geographic Database) server to lookup location of IP addresses, unfortunately this database is not maintained anymore and may return <em>wildly incorrect</em> data.
diff --git a/lib/adminlib.php b/lib/adminlib.php
index b14741ef7a4..c3e39cd1e1f 100644
--- a/lib/adminlib.php
+++ b/lib/adminlib.php
@@ -3614,14 +3614,15 @@ class admin_setting_configiplist extends admin_setting_configtextarea {
      */
     public function validate($data) {
         if(!empty($data)) {
-            $ips = explode("\n", $data);
+            $lines = explode("\n", $data);
         } else {
             return true;
         }
         $result = true;
         $badips = array();
-        foreach($ips as $ip) {
-            $ip = trim($ip);
+        foreach ($lines as $line) {
+            $tokens = explode('#', $line);
+            $ip = trim($tokens[0]);
             if (empty($ip)) {
                 continue;
             }
diff --git a/lib/moodlelib.php b/lib/moodlelib.php
index 446807ef262..34fe56bb108 100644
--- a/lib/moodlelib.php
+++ b/lib/moodlelib.php
@@ -8888,7 +8888,7 @@ function cleardoubleslashes ($path) {
 }
 
 /**
- * Is current ip in give list?
+ * Is the current ip in a given list?
  *
  * @param string $list
  * @return bool
@@ -8903,8 +8903,9 @@ function remoteip_in_list($list) {
     }
 
     $list = explode("\n", $list);
-    foreach ($list as $subnet) {
-        $subnet = trim($subnet);
+    foreach ($list as $line) {
+        $tokens = explode('#', $line);
+        $subnet = trim($tokens[0]);
         if (address_in_subnet($clientip, $subnet)) {
             $inlist = true;
             break;