Point to remember for CISA Exam:
CISA aspirant should be aware about layer of OSI at which below devices operate.
Hub – Physical Layer (1st Layer)
Switch – Data Link Layer (2nd Layer)
Bridge – Data Link Layer (2nd Layer)
Router – Network Layer (3rd Layer)
Gateway-Application Layer (7th Layer)
It must be noted that higher the layer, more intelligent the devices will be. Out of above Hub (layer 1) is dumbest device and Gateway (layer 7) is the most intelligent device.