diff --git a/includes/discovery/discovery-protocols.inc.php b/includes/discovery/discovery-protocols.inc.php
index 16d9a778c..d3ce599b8 100755
--- a/includes/discovery/discovery-protocols.inc.php
+++ b/includes/discovery/discovery-protocols.inc.php
@@ -57,7 +57,7 @@ if ($cdp_array)
     foreach (array_keys($cdp_if_array) as $entry_key)
     {
       $cdp = $cdp_if_array[$entry_key];
-      if (ctype_alnum($cdp['cdpCacheDeviceId']))
+      if (ctype_alnum(str_replace('.','',$cdp['cdpCacheDeviceId'])))
       {
         $remote_device_id = @mysql_result(mysql_query("SELECT `device_id` FROM `devices` WHERE `sysName` = '".$cdp['cdpCacheDeviceId']."' OR `hostname`='".$cdp['cdpCacheDeviceId']."'"), 0);