Improve routes in all aspects of vswitch port cascade knowledge

Switch Port cascade knowledge to improve the route, when the two ports are common ports, namely MDI-X) port and MDI-II port, should use a straight-through cable. When four vswitches are uplinked, the network span can reach 500 meters. This distance is enough for a small network in the same building!

Port cascade of twisted pair Switches

Cascade uses both common ports and special MDI-II ports. A straight-through cable should be used when the two ports that are cascaded are normal ports (MDI-X) ports and MDI-II ports, respectively. Cross-cable should be used when both ports of mutual cascade are common ports, that is, MDI-X) or both are MDI-II ports.

Whether it is 10Base-T Ethernet, 100Base-TX fast Ethernet, or 1000Base-T Gigabit Ethernet, the length of the cable used by the cascade switch can reach 100 meters, which is exactly the same length as that between the switch and the computer. Therefore, in addition to expanding the number of ports, cascade is also used to quickly extend the network diameter. When four vswitches are uplinked, the network span can reach 500 meters. This distance is enough for a small network in the same building!

Use Uplink switch port Cascade

Now, more and more switches except Cisco switches) provide Uplink ports to simplify the connection between switches. Uplink port is a port dedicated for connecting to other vswitches. You can use a straight-through jumper to connect this port to any port other than the Uplink port of other vswitches, the connection method is the same as that between the computer and the switch. Note that some brands of vswitches such as 3Com use a common port and Uplink port, and use an MDI/MDI-X switch) to switch between the two types.

Use common switch port Cascade

If the vswitch does not provide a dedicated cascade port Uplink port), the common ports of the two vswitches can only be connected using a jumper to expand the number of Network Ports. When using a common port to connect to a vswitch, you must use a cross line instead of a direct line.

Optical Switch Port Cascade

Because Fiber ports are still very expensive, fiber cables are mainly used for connection between core switches and backbone switches, or for cascade between backbone switches. Note that all optical fiber ports are not stacked and can only be used for Cascade.

Optical jumper crossover

Each vswitch has two fiber-optic ports, one for one request. Of course, the optical fiber jumper must also be two; otherwise, communication between ports fails. When a vswitch is cascade through an optical fiber port, both ends of the optical fiber jumper must be sent and received. When one end is "received", the other end is "sent ".

Similarly, when one end is connected with "sending", the other end is connected with "receiving ". It is gratifying that the Cisco GBIC optical fiber module is labeled with a sending and receiving sign. The arrows on the left side indicate "receiving", and the arrows on the right side indicate "sending ". If both ends of the optical jumper are connected to "receive" or "send", the LED light on the port is not on, indicating that the connection is failed. The LED indicator turns green only when the optical fiber port is successfully connected. Similarly, when the backbone switch is connected to the core switch, the optical fiber receiving and receiving ports must also be cross-connected.

Optical jumper and port cascade type of Optical Switch

Jumper cables are divided into single-mode optical fiber and multi-mode optical fiber. The optical fiber port and jumper of the switch must be consistent with the optical fiber type used in the Integrated Wiring. That is to say, if the multi-mode optical fiber is used in the Integrated Wiring, the optical fiber interface of a vswitch must comply with the 1000Base-SX standard and multimode optical fiber jumper. If the single-mode optical fiber is used in integrated wiring, the optical fiber interface of the vswitch must comply with the 1000Base-LX/LH standard, the Single-Mode Optical Fiber jumper must also be used.

Note that Multimode Optical Fiber has two types: 62.5/125 μM and 50/125 μM. Although the optical fiber ports of the vswitch are identical and both adopt the 1000Base-SX standard, the core diameter of the optical fiber jumper must be the same as that of the optical fiber jumper. Otherwise, the connectivity will fail. In addition, the type of the fiber ports to be connected must be the same, or both are multimode fiber ports or single-mode fiber ports. One end is a Multimode Optical Fiber port, while the other end is a single-mode optical fiber port, which cannot be connected together.

Transmission Rate and duplex mode

Unlike 1000Base-T, 1000Base-SX, 1000Base-LX/LH, and 1000Base-ZX do not support self-adaptation. Ports of different speed and duplex working modes cannot connect and communicate. Therefore, it is required that the port cascade of the fiber-optic switch must have the same transmission rate and duplex working mode, so that the fiber-optic port of Mbps cannot be connected together with the fiber-optic port of Mbps, the full-duplex mode fiber port cannot be connected with the half-duplex mode fiber port. Otherwise, the connectivity will fail.