oooppss. i missed an information. you have a dlink dl-524 router. we have the same router and dlink already discontinued the production of that router and when i checked it, it seems that it's not equip with snmp protocol and i am still trying to look for it and how to enable it if there's any.
heh hope that you come with some way to enable it in di-524 ;) and as for this router, i dunno if this router is old or not i buy'ed it as new in shop like a 2 month's ego O_o