Chọn phương tiện truyền thông thích hợp, dây cáp, bến cảng, và kết nối để kết nối các thiết bị chuyển mạch với các thiết bị mạng và các host khácEthernet cáp là một cuộc thảo luận quan trọng, đặc biệt là nếu bạn đang có kế hoạch tham gia các kỳ thi Cisco. | 68 Chapter 2 Configure verify and troubleshoot a switch with VLANs Select the appropriate media cables ports and connectors to connect switches to other network devices and hosts Ethernet cabling is an important discussion especially if you are planning on taking the Cisco exams. Three types of Ethernet cables are available Straight-through cable Crossover cable Rolled cable We will look at each in the following sections. Straight-Through Cable The straight-through cable is used to connect Host to switch or hub Router to switch or hub Four wires are used in straight-through cable to connect Ethernet devices. It is relatively simple to create this type Figure shows the four wires used in a straight-through Ethernet cable. FIGURE Straight-through Ethernet cable Hub Switch Host 1 1 2 - ------------------------ 2 3 - ----------------------- - 3 6 ------------------------- - 6 Notice that only pins 1 2 3 and 6 are used. Just connect 1 to 1 2 to 2 3 to 3 and 6 to 6 and you ll be up and networking in no time. However remember that this would be an Ethernet-only cable and wouldn t work with voice Token Ring ISDN and so on. Crossover Cable The crossover cable can be used to connect Switch to switch Hub to hub Select the appropriate media cables ports and connectors to connect switches 69 Host to host Hub to switch Router direct to host The same four wires are used in this cable as in the straight-through cable we just connect different pins together. Figure shows how the four wires are used in a crossover Ethernet cable. Notice that instead of connecting 1 to 1 2 to 2 and so on here we connect pins 1 to 3 and 2 to 6 on each side of the cable. FIGURE Crossover Ethernet cable Rolled Cable Although rolled cable isn t used to connect any Ethernet connections you can use a rolled Ethernet cable to connect a host to a router console serial communication com port. If you have a Cisco router or switch you would use this cable to connect your PC running .
