nilesh
There are two ways to accomplish what your drawing seems to show. I say seems to show because the drawing is ambiguous about the connection of the switch to the 3745. If that connection is a trunk carrying multiple VLANs then you want to configure subinterfaces on the 3745 interface to accomodate the VLANs and to provide inter-VLAN routing. But when the drawing shows it as an unmanaged switch I wonder if the connection could possibly be a trunk.
If the connection is not a trunk then all of the ports are in a single broadcast domain (single VLAN or whatever terminology that you want to use). The solution would be to use secondary addressing on the Ethernet of the 3745. While the configuration would look like you have separate subnets and the benefits that different subnets have (limiting broadcasts, etc) the reality is that all the devices are in the same broadcast domain. Every machine will see all the broadcasts from every other machine. Every PC can potentially ARP for any other PC and they could communicate directly, without needing the router.
The drawing suggests that you are attempting to isolate the traffic of each floor. But the choice of unmanaged switches does not support that.
HTH
Rick
HTH
Rick
