I am planning a solution for a multi-tenant office building. There are Catalyst layer 2 managed switches in place. They want to give about 40 separate businesses their own access to the 50Mbps internet pipe but isolate each one's traffic. I'd like to accomplish this with a router or firewall. I'm thinking of using a 1941 with multiple VLAN's and subinterfaces, and also use the router to handle DHCP for these multiple subnets. Is it a reasonable solution in terms of performance and configuration, or should I choose another model.