A switch means that a switch is a network device used for electrical (optical) signal forwarding. It provides an exclusive electrical signal path for any two network nodes that access the switch. The most common switch is an Ethernet switch. Other common telephone voice switches, fiber switches, and so on.

A switch is a network device that uses a very wide range of network devices and multiple network devices. A switch is an essential device.

      165/5000Gè zhǒng jiāohuànjī jiēkǒu

jiāohuànjī de jiēkǒu fēicháng fēngfù, zhèlǐ shì yīxiē zhěnglǐ de zīliào, yǔ dàjiā fēnxiǎng.

1,RJ-45 jiēkǒu

zhè zhǒng jiēkǒu jiùshì wǒmen xiànzài zuì chángjiàn de wǎngluò shèbèi jiēkǒu, súchēng"shuǐjīng tóu", zhuānyè shùyǔ wèi RJ-45 liánjiē qì, shǔyú shuāng jiǎo xiàn yǐtài wǎng jiēkǒu lèixíng.RJ-45 chātóu zhǐ néng yán gùdìng fāngxiàng chārù, shè yǒu yīgè sùliào dànpiàn yǔ RJ-45 chā cáo kǎ zhù yǐ fángzhǐ tuōluò.Various switch interfaces

       The interface of the switch is very rich. Here are some sorted materials to share with you.

       1, RJ-45 interface

       This interface is the most common network device interface we have now, commonly known as "Crystal Head", the terminology is RJ-45 connector, which is a twisted pair Ethernet interface type. The RJ-45 plug can only be inserted in a fixed direction, with a plastic dome attached to the RJ-45 slot to prevent it from falling out.

This interface can be used in 10Base-T Ethernet, 100Base-TX Ethernet, 1000Base-TX Ethernet, and the transmission medium is twisted pair. However, depending on the bandwidth, the medium also has different requirements, especially 1000Base- When connecting to a Gigabit Ethernet connection, use at least a Category 5 cable. To ensure stable high speed, use Category 6 cable.

       2, SC fiber interface

       The SC fiber interface has been used in the 100Base-TX Ethernet era, so it was called 100Base-FX (F is the abbreviation of fiber word fiber), but at that time, because the performance is not more prominent than the twisted pair, but the cost is higher, so Not popularized, the industry is now promoting Gigabit networks, and SC fiber interfaces are re-emphasizing.

There are many types of fiber interfaces. SC fiber interfaces are mainly used in the local area network switching environment. This interface is provided on some high-performance Gigabit switches and routers. It looks similar to the RJ-45 interface, but the SC interface is more flat. The obvious difference is the contact inside. If it is 8 thin copper contacts, it is the RJ-45 interface. If it is a copper column, it is the SC fiber interface.

       3, AUI interface

       The AUI interface is specifically used to connect thick coaxial cables. On the early network cards, such interfaces were connected to hubs and switches to form a network, which is generally not used now.

      AUI接口是一种"D"型15针接口，之前在令牌环网或总线型网络中使用，可以借助外接的收发转发器(AUI-to-RJ-45)，实现与10Base-T以太网络的连接。

      4、FDDI接口

      FDDI是目前成熟的LAN技术中传输速率最高的一种，具有定时令牌协议的特性，支持多种拓扑结构，传输媒体为光纤。

      光纤分布式数据接口(FDDI)是由美国国家标准化组织(ANSI)制定的在光缆上发送数字信号的一组协议。FDDI使用双环令牌，传输速率可以达到100Mbps。

      CCDI是FDDI的一种变型，它采用双绞铜缆为传输介质，数据传输速率通常为100Mbps。

      FDDI-2是FDDI的扩展协议，支持语音、视频及数据传输，是FDDI的另一个变种，称为FDDI全双工技术(FFDT)，它采用与FDDI相同的网络结构，但传输速率可以达到200Mbps。

      由于使用光纤作为传输媒体具有容量大、传输距离长、抗干扰能力强等多种优点，常用于城域网、校园环境的主干网、多建筑物网络分布的环境，于是FDDI接口在网络骨干交换机上比较常见，现在随着千兆的普及，一些高端的千兆交换机上也开始使用这种接口。

      5、Console接口

      这个接口我们知道，它是用来配置交换机的，所以只有网管型交换机才有。而且还要注意，并不是所有网管型交换机都有，那是因为交换机的配置方法有多种，如通过Telnet命令行方式、Web方式、TFTP方式等。虽然理论上来说，交换机的基本配置必须通过Console（控制）端口，但有些品牌的交换机的基本配置在出厂时就已配置好了，不须要进行诸如IP地址、基本用户名之类的基本配置，所以这类网管型交换机就不用提供这个Console接口了，而且就目前来说还占多数。这类交换机通常只需要通过简单的Telnet或Java程序的Web方式进行一些高级配置即可。

      当然也有一些交换机还是提供了Console接口的，但要注意的是，用于交换机配置的Console端口并不是所有交换机都一样，有的采用与Cisco路由器一样的RJ-45类型Console接口，如图所示。