DS200TCPDG2BEC 根据帧头的目的MAC地址查找MAC地址表

Description

DS200TCPDG2BEC 根据帧头的目的MAC地址查找MAC地址表

以太网交换机是基于以太网传输数据的交换机，DS200TCPDG2BEC采用共享总线型传输媒体方式的局域网。以太网交换机的每个端口都可以直接与主机相连，并且一般以全双工模式工作。以太网交换机结构是每个端口都直接与主机相连，并且一般以全双工模式工作。交换机能同时连通许多对的端口，使每一对相互通信的主机都能像独占通信媒体那样进行无冲突地传输数据。

以太网交换机是一种基于MAC地址识别、完成以太网数据帧转发的网络设备。其工作原理是交换机在端口上接受计算机发送过来的数据帧，根据帧头的目的MAC地址查找MAC地址表，然后将该数据帧从对应端口上转发出去，从而实现数据交换。此外，以太网交换机应用最为普遍，价格也较便宜，档次齐全，因此其应用领域非常广泛。

DS200TCPDG2BEC 以太网交换机通过以下步骤进行数据交换：

直通方式：以太网交换机在各端口间建立纵横交叉的线路矩阵，在输入端口检测到一个数据包时，检查该包的包头，获取包的目的地址，启动内部的动态查找表转换成相应的输出端口，在输入与输出交叉处接通，把数据包直通到相应的端口，实现交换功能。由于不需要存储，延迟非常小、交换非常快，这是它的优点。但它的缺点是，因为数据包内容并没有被以太网交换机保存下来，所以无法检查所传送的数据包是否有误，不能提供错误检测能力。由于没有缓存，不能将具有不同速率的输入/输出端口直接接通，而且容易丢包。

存储转发方式：存储转发方式是计算机网络领域应用最为广泛的方式。以太网交换机把输入端口的数据包先存储起来，然后进行CRC(循环冗余码校验)检查，在对错误包处理后才取出数据包的目的地址，通过查找表转换成输出端口送出包。这种方式可以对传输错误的数据包进行检查，但需要较长的时延。

DS200TCPDG2BEC 根据帧头的目的MAC地址查找MAC地址表

Ethernet switch is a switch based on Ethernet to transmit data. DS200TCPDG2BEC is a LAN with shared bus transmission media. Each port on an Ethernet switch can be directly connected to a host and generally works in full duplex mode. The Ethernet switch structure is that each port is directly connected to the host, and generally works in full duplex mode. The switch can connect many pairs of ports at the same time, so that each pair of hosts communicating with each other can transmit data without conflict as if they were exclusive communication media.

Ethernet switch is a network device that realizes Ethernet frame forwarding based on MAC address recognition. The working principle is that the switch accepts the data frame sent by the computer on the port, finds the MAC address table according to the destination MAC address of the frame header, and then forwards the data frame from the corresponding port to achieve data exchange. In addition, the Ethernet switch is the most common application, the price is also cheaper, the grade is complete, so its application field is very wide.

The DS200TCPDG2BEC Ethernet switch uses the following steps to exchange data:

Through mode: The Ethernet switch establishes a crosswise line matrix between ports. When a packet is detected on the input port, the switch checks the packet header, obtains the destination address of the packet, and starts the internal dynamic lookup table to convert the packet to the corresponding output port. When the input and output are connected at the intersection, the packet is passed through to the corresponding port to realize the switching function. Since no storage is required, the latency is very small and the exchange is very fast, which is its advantage. However, its disadvantage is that because the packet content is not saved by the Ethernet switch, it cannot check whether the transmitted packet is wrong, and it cannot provide error detection capability. Since there is no cache, input/output ports with different rates cannot be directly connected, and it is easy to lose packets.

Store-and-forward mode: store-and-forward mode is the most widely used mode in the field of computer network. The Ethernet switch stores the data packets at the input port first, then performs CRC(cyclic redundancy code check) check, and takes out the destination address of the data packet after processing the error packet, and converts the data packets to the output port through the lookup table. In this way, incorrect packets can be checked, but the delay is long.