Do not chain L3 devices

Never ever chain-connect L3 devices. In situation when you need to add additional device to a segment which exists between two routers only you will have to redo wiring and reconnect everything to switch fabric.





All L3 interfaces of all segments should be connected to a switch fabric directly. The only valid reason to connect L3 interfaces back-to-back directly is keeping segments isolated. However, the isolation can be achieved with SVI absence in segment in question.