Okay, you are not going to be able to do this using the interconnect between the switch and the router. The issue is -
1) if you make the interconnect a L2 trunk then you would have subinterfaces on the router interface connecting to the switch. But you cannot have multiple interfaces on the router configured from the same IP range so it won't work ie. you would need a subinterface using the same IP range as one of the other interfaces
2) if you make the interconnect L3 as you have then you cannot route to the same subnet ie. think of it as two separate devices, a L3 switch and a router. You connect the L3 switch to the router using a L3 connection.
On the switch you then configure a client with a public IP and on another interface on the router ie. not the interface used to connect to the switch, you use the same public IP range.
You cannot then route from the client to that other interface because you don't route to the same IP subnet and the client and the other interface are separated by a different IP subnet.
So neither will work. The L3 switch is usually used where you have multiple vlans/IP subnets and you create L3 vlan interfaces for these on the switch and then you route to other subnets that are reachable from the router, whether these are directly connected subnets or remote networks.
But you aren't doing that.
The only way i could see you doing what you need is to not configure the interconnect at all and instead run cables from the relevant router interfaces to the switch. Then you could configure vlans on the switch and have them route via the physical router interface.
The switch is then only acting as a L2 switch and all L3 is done on the router.
One thing i should say is i have never used the switch module this way so i can't guarantee it will work although i can't see why it wouldn't.
Jon
