S-port
The meaning of Serial interface, also known as high-speed asynchronous serial port, is mainly used to connect the cable of the WAN, in other words, it is used when the router and the router are connected, and the bandwidth can be set by command, generally around 10M or 8M.

e-port
It is an Ethernet interface, called the Ethernet interface, which is also mainly used to connect the Ethernet (local area network), and it can be connected with an ordinary twisted pair, the default rate is 10Mbps, and now the interface has been eliminated on the new equipment. In addition, there is an essential interface on the router is the Console port, called the control port, this interface is used to debug the router. Some routers have AUX interface, which is also a control interface; There is also a G port, which is a Gigabit Ethernet interface and is used to connect to Ethernet.

f-port
It's a FastEthernet interface, a fast Ethernet port, also called a hundred-megabit port. The main connection Ethernet (local area network) is used, which is to connect the switch or the computer, with an ordinary twisted pair can be connected, the default rate is 100Mbps, you can use the command speed limit, but it is impossible to exceed 100Mbps

g-port
Port G stands for Gigabitethernet, which means Gigabit port. Gigabit only means that it is a gigabit port. Whether it is an optical port or an electrical port, the display is the same. If you want to see it in detail, you can display int to view it.

GigabitEthernet can be an optical interface or an electrical interface, depending on the device parameters. Ethernet is an Ethernet port, GigabitEthernet is a GigabitEthernet port, both of which are defined by the IEEE 802.3 standard and can use network cables or optical fibers.