I just purchased a Catalyst 5509 switch with the supervisor III engine and 8 24 port switch modules, however, it doesn't have a Router Switch Module. What kind of router would I need to be able to define a trunked port out to the router to do inter-vlan routing? I currently have 2 831's, but i'm assuming that these won't work, seing as though they don't support trunking on the ethernet ports...