On the back of the home broadband router, there are usually four "cat-mouth" jacks, which represent four physical interfaces and are marked as LAN 1, LAN2, LAN3 and LAN4 respectively. These interfaces are usually used to connect various wired devices, such as computers, printers, televisions, etc.

There is no difference in function between these four interfaces, and they can all be connected with wired devices. Generally speaking, when multiple devices need wired access to the Internet, these four interfaces can be used to connect routers by wired means.

It should be noted that one of the interfaces is usually a WAN port, which is usually marked as Internet or WAN port, so I won't go into details here.

In addition, in order to meet the needs of more users and various devices for high-speed Internet access, some home broadband routers are also equipped with some higher-speed interfaces, such as USB3.0 or 10GSFP+ interface. , but these interfaces are not the main wired interfaces, so users generally don't need to pay special attention.

In a word, the jacks LAN 1, LAN2, LAN3 and LAN4 behind the Cat's Mouth at home are four identical physical interfaces, which are used to connect various wired devices to achieve the purpose of network connection.