Looping back through switches?

Question

Please look at the attached topology

I am studying for CCNP with ine.com, and I have got a lab switch they say is possible, I say it is not (with the current config)

SW-3 config

Fa 0/15
no switchport
ip address 1.1.1.33

Fa 0/14
switchport trunk encapsulation dot1q
switchoort mode trunk

Fa 0/3
switchport mode access
switchport access vlan 111

SW-1 config

Fa 0/15
switchport mode access
switchport access vlan 111

Fa 0/11
switchport mode access 
switchport access vlan 111

Fa 0/14
switchport trunk encapsulation dot1q
switchoort mode trunk

SW-2 config

Fa 0/11
no switchport
ip address 1.1.1.22

R3

Fa 0/1
ip address 1.1.1.111

The problem

SW-3 Fa0/15 generates an icmp packet headed for 1.1.1.111 (which is R3), it never makes it. (This is indicated by the red line)

SW-2 Fa0/11 generates an icmp packet headed for 1.1.1.111 (which is R3), it makes it. (This is indicated by the blue line)

SW-1, SW-3, SW-2 all have ip routing enabled.

If R3 generates the packet, heading for 1.1.1.33 (SW-3 int Fa 0/15) when the packet gets to SW-3, I believe the switch looks at its cef table and sees that 1.1.1.33/32 has received beside it not attached. So it thinks that the packet is for itself, and does not attempt to forward it out any interface.

I think this is somehow causing conflict, as the packet needs to be forwarded out Fa 0/14 and then back in Fa 0/15

If anyone could point me in the right direction I would be very grateful.

Answer 1

Im sure this is a limitation with the 3550.

SW-3 is the 3550, i have just used a 3560 and it works fine.