Each physical cisco interface comprises of a hardware IDB andat least one software. The post below shows all the important physical interfaces in a Cisco Router.
• Ethernet – Ethernet is typically Ethernet IEEE 802.3 standard based physical interface, which operates at 10 Mbps speed. The media standard used is 10BaseT.
• Fast Ethernet – Fast Ethernet is typically Ethernet IEEE 802.3u standard based physical interface which operates at 100 Mbps speed. The
media standard used is 100BaseT.
• Gigabit Ethernet – Gigabit Ethernet is typically Ethernet IEEE 802.3ab standard based physical interface which operates at 1000 Mbps speed. The media standard used is1000BASE-T
• Serial: Serial interfaces are typically used for WAN connections from ISP (Internet Service Providers) for connectivity types like Frame Relay, T1, T3, etc
FDDI Fiber Distributed Data Interface. – FDDI networks operates at 100 Mbps speed and uses a token-passing mechanism to prevent collisions.
• Token Ring – Token Ring interfaces can operate at either 4 Mbps or 16 Mbps. In Token Ring networks atoken is passed around the network (configured in ring topology), allowing the owner of the tokento transmit a frame, to avoid collision.Token Ring networks vanished fromnetworking industry long way back. New Cisco routers do not have a Token Ringinterface.
Note : Only 10Mbps Ethernet interface has a name”Ethernet” in a Cisco Router. A 100Mbps Ethernet interface is calleda “FastEthernet” interface and a 1000Mbps Ethernet interface iscalled a “GigabitEthernet” interface.
Virtual interfaces are alsoavailable in a Cisco Router. Examples of virtual interfaces are loopback interface and Null interface.