Cisco router different types of interfaces

The auxiliary and console ports are used for the router management. Routers also have ports for LAN and WAN connectivity. The LAN interfaces usually include Ethernet, Fast Ethernet, and GigaEthernet ports. Fiber Distributed Data Interface (FDDI), or Token Ring. Following is the detail of all types of interfaces of Cisco routers.

Ethernet

Ethernet is typically Ethernet IEEE 802.3 standard based physical interface. This port is operating at 10 Mbps speed. The media standard for this interface is 10BaseT.

Fast Ethernet

The Fast Ethernet is typically Ethernet IEEE 802.3u standard based physical interface. Fast Ethernet cards connect to networks at a rate of 100 Mbps. The media standard used for this interface is 100BaseT. Fast Ethernet is also called FE interfaces.

Gigabit Ethernet

Gigabit Ethernet is called GE interface. This ports standard is Ethernet IEEE 802.3ab. Gigabit network cards can connect at speeds up to 1000mb/s. The media standard used is1000BASE-T

Serial interfaces

A serial interface is a communication interface between two digital systems that transmit data as a series of voltage pulses down a wire.Serial interfaces are typically used for WAN connections from ISP  to host. serial interface provides connectivity types like Frame Relay, T1, T3, etc

FDDI

Fiber Distributed Data Interface is a set of ANSI and ISO standards for data transmission on fiber optic lines in a local area network (LAN). The range of FDDI can extend in range up to 200 km. FDDI networks operate at 100 Mbps speed and use a token-passing mechanism to prevent collisions.

Token Ring

A token ring network is a local area network (LAN) in which all computers are connected in a ring or star topology and pass one or more logical tokens from host to host. Only a host that holds a token can send data, and tokens are released when receipt of the data is confirmed. Token Ring interfaces can operate at either 4 Mbps or 16 Mbps.Token Ring networks missing from networking industry long way back. New Cisco routers do not have a Token Ring interface.

Loopback interface

A loopback interface is a logical, virtual interface in a Cisco Router. This type of interface is not a physical interface like Fast Ethernet interface or Gigabit Ethernet interface. A loopback interface has many uses. Loopback interface's IP Address determines a router's OSPF Router ID.

Null Interface

A null interface is a virtual interface that discards IP packets and is used to prevent routing loops from occurring in the network. We do not assign the IP address to a null interface.