I don't not think there is a way without patching snmp.c prior to PHP configuring. You can always do: $segment = explode(":", $macaddress); foreach($segment as $seg){ $hex[] = str_pad($seg, 2, 0, STR_PAD_LEFT); } $macaddress = implode(":", $hex); or use a preg replace function and match Mike Mackintosh PHP, the drug of choice - www.highonphp.com On Mar 15, 2012, at 4:12 PM, David OBrien wrote: > Using command line snmpget you can set an option to append leading 0's to > hex values -o0 > So instead of > > $macaddress = "0:1a:4b:c:8d:fb"; > > it would be > > $macaddress = "00:1a:4b:0c:8d:fb"; > > is there any option using the extremely well documented php snmp extension > to do the same?