1900 Series Switch
2900/2950 Series Switch
The 1900 series switch has either 12 or 24 Ethernet ports named e0/1, e0/2, ... e0/24. There is also an Ethernet port named e0/25 that is in the back of the switch using an AUI interface. Ports A and B on the front of the switch are named fa0/26 and fa0/27, respectively, regardless of the switch is a 12-port or 24-port model. Ports A and B are Fast Ethernet.
The 2900 and 2950 series switches have either 12 or 24 Fast Ethernet ports named fa0/1, fa0/2, ... fa0/24.