First attempt at L3 switching

I put the ip helper-address on the VLAN interfaces on S1, so that the PC and Mac can receive ip addresses from the DHCP server.

The big difference I see between my attempts of router-on-a-stick and L3 switching is that for L3 switching, you use the VLAN interfaces to assign IP addresses on the L3 switch as the gateways for the hosts in the designated VLAN.  

For router-on-a-stick, you create sub-interfaces (Fa0/0.10) on the router interface, assign IP addresses to those interfaces, set encapsulation dot1q on the sub-interface, because you are connected to a switch port that is trunking, and then you tell it what VLAN to forward.