The straight, cross, and reverse lines in Ethernet cables are classified according to their different line sequences, and they have specific applications in different network connection scenarios. This article will introduce the specific analysis and application scenarios of these three types of line sequences.
一, Direct connection
1. Line sequence: The two ends of the straight line have the same line sequence, that is, pin 1 corresponds to pin 1, pin 2 corresponds to pin 2, and so on.
2. Standard: Usually following T568A or T568B standards.
3. Specific line sequence:
T568A: White green, green, white orange, blue, white blue, orange, white brown, brown
T568B: White Orange, Orange, White Green, Blue, White Blue, Green, White Brown, Brown
4. Application scenarios:
Computer to switch: Connect the computer's network card (NIC) to the switch.
Router to switch: Connect the LAN port of the router to the switch.
Switch to switch: Connect two switches of different brands.
From modem to router: Connect the WAN port of the modem to the WAN port of the router.
Printer to switch: Connect the network printer to the switch.
二, Cross line
1. Line sequence: One end of the crossover line adopts T568A standard, and the other end adopts T568B standard, or the 1st and 3rd pins, 2nd and 6th pins of the two are interchanged.
2. Standard: Usually used to connect two devices of the same type.
3. Specific line sequence:
T568A one end: white green, green, white orange, blue, white blue, orange, white brown, brown
T568B other end: white orange, orange, white green, blue, white blue, green, white brown, brown
4. Application scenarios:
Computer to Computer: A network card that directly connects two computers for file sharing or temporary networking.
Switch to switch: Connect two switches of the same brand for stacking or expanding a network.
Router to router: Connect the LAN ports of two routers for network interconnection.
Switch to Hub: Connect switches and hubs to expand the network.
三, Reverse Line
1. Line sequence: The line sequence at one end of the reverse line is completely reversed, with pin 1 corresponding to pin 8, pin 2 corresponding to pin 7, and so on.
2. Standard: Console Port typically used to connect network devices.
3. Specific line sequence:
One end: white orange, orange, white green, blue, white blue, green, white brown, brown
On the other end: brown, white brown, green, white blue, blue, white green, orange, white orange
4. Application scenarios:
Computer to Router Console: Connect the computer's serial port to the router's console port for configuring and managing the router.
Computer to switch console: Connect the computer's serial port to the switch's console port for configuring and managing the switch.
Computer to other network device console: Connect the computer's serial port to the console port of other network devices (such as firewalls, wireless access points) for configuring and managing devices.
四, Summary
Direct connection: used to connect different types of devices, such as computers to switches, routers to switches, etc.
Crossover: Used to connect devices of the same type, such as computer to computer, switch to switch, etc.
Reverse line: Used to connect the console port of network devices, such as the console port from a computer to a router or switch.
Understanding these cable sequences and their application scenarios can help select the appropriate cable type for network connectivity and device configuration, ensuring the normal operation and efficient management of the network.
