(packettracer is a simulation software developed by Cisco Enterprises for its CCNA certification to design, configure, and troubleshoot networks. Users create their own network topology and configure the devices in that topology through a graphical interface. The software also provides a packet transmission simulation function for users to investigate the transmission process of packets in the network. Because the English interface has brought a lot of inconvenience to many brothers with poor English foundation, I will not upload the software to teach you. After you search online, I have a PacketTracer5.0 Chinese patch and tutorial to download, which is convenient for CISCO to download. for beginners to learn! !!)