Explanation of vswitch fiber port problems

What is a vswitch fiber port? What is the optical fiber port of a vswitch? What is the difference between a fiber-optic port of a vswitch and a common port? After reading this article, you will know a lot and hope you can learn more.

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!

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 to "send", the other end is connected to "receive" 4 ). 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.

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. Cascade is connected to other hubs through a port of the hub.

For example, a UPLINK port of a hub is used to connect to another normal port, while a stack is connected through the hub backplane. It is a chip-level connection, for example, the stacking of two 24-port switches is like a 48-port switch. The advantage is that it will not produce bottlenecks.

Stack and Uplink are two ways to connect multiple switches or hubs. Their main purpose is to increase the port density. However, their implementation methods are different. In short, cascade can be completed between switches, between hubs, or between switches and hubs of any network equipment manufacturer through a twisted pair.

Stack is only available between devices of your own manufacturer, and the device must have a stack function. Cascade a single twisted pair (or other media) requires a dedicated Stacking Module and cable, and these devices may need to be purchased separately. In theory, there is no limit on the number of cascade switches (Note: The number of cascade switches is limited, and the requirements for 10 M and M are different ), the devices of each stack manufacturer indicate the maximum number of stacks.

It can be seen from the above that the cascade is easy, but the technology of stacking has the advantages that cascade cannot achieve. First, multiple switches are stacked together. Logically, they belong to the same device. In this way, if you want to set these switches, you only need to connect to any device and you can see other switches in the stack. Cascade devices are logically independent. If you want to manage these devices, you must connect them to each device in sequence.

Second, multiple device-level associations cause cascade bottlenecks. For example, if two 10-Gigabit switches are connected through a twisted pair, their cascade bandwidth is Mbps. In this way, computers of different vswitches can only communicate with each other through the mbps bandwidth.

The two switches are connected together through stacks, And the stacked cables can provide a bandwidth higher than 1g, greatly reducing the bottleneck. Now there is a new technology for vswitches-Port Trunking. With this technology, you can use multiple twisted pair wires to cascade two vswitches to increase the cascade bandwidth.

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