Nomenclature Guide | Router and Switch | Port, Slot, Interface

          Cisco nomenclature is very important to know for examination as well as when it comes to configuring the components of a specific interface. 

Switch Interface Nomenclature

          Some Catalyst series switches support only fixed interface, while some of higher end switches support Modular slots with interface card. 

          The nomenclature of an interface is type slot_#/port_#.

Nomenclature	Description
type	The type of interface is the media type, such as ethernet, fast ethernet, or gigabit.
slot_#	Slot number. For all fixed interfaces, the slot number is always 0.
port_#	Define the number of the port in the specific slot. starts at 1 and so on.

          Example: For instance, you have a switch with First Ethernet and the nomenclature for the very first interface would look like this: fastethernet 0/1, second fastethernet 0/2 and so on. If you have gigabit Ethernet then the interface called gigabitethernet 0/1.

Router Interface Nomenclature

          Depending on what Cisco router you purchase or have, Cisco routers interface comes with either fixed, modular, or a combination of the two. Also supports many different data link layer media types: atm, asynch, bri, ethernet, fastethernet, gigabitethernet, and serial, as well as many others.

Fixed Interface:

          If your Router has a fixed interface it will always start counting from 0 and so on and the nomenclature is type port_#. Assume your router has two fixed serial and two fixed ethernet port, and the would-be called serial 0 and serial 1, and ethernet 0 and ethernet 1.

Note: Port number starts with 0 for each interface, and for multiple interfaces, by interface type and number can uniquely be identified.

Modular Slot:

          You can insert interface into modular slots if your router supports, in this case, the nomenclature will be similar to switch have: type slot_#/port_#.

Note: Router Slot number began with 0

          Assume you have a router with two ethernet modular slots with 2 port each. So the nomenclature would be like ethernet 0/1, ethernet 0/2 and ethernet 1/1, ethernet 1/2. What if, if you have three port serial module in the third slot of a router, well in this time the nomenclature would be serial 2/0, serial 2/1, serial 2/2,