Master high-end switch cascade to instantly become a master of the Network

Master the high-end switch cascade to instantly become a master of the network, previously introduced the relevant knowledge. After the publication of the stack and cascade of switches, we have received a number of emails from many readers to discuss with us about the cascade of switches. So we will introduce some related content about high-end switch cascade.

High-end switch cascade: optical transceiver connection

When optical cables are used for cabling between buildings or between floors, and horizontal cabling uses twisted pair wires, two transmission media connections can be implemented. One is the use of both fiber port and RJ-45 port switch, In the switch to achieve the interconnection between the optical port; the second is the use of cheap photoelectric conversion equipment, one end is connected to one end of the optical fiber to connect the twisted pair port of the vswitch, achieving mutual conversion between the optical fiber. 1 shows the optical transceiver.

Figure 1 high-end switch-level optical transceiver

In comparison, a modular switch provides higher transmission performance, while a photoelectric conversion device is cheaper. Therefore, the device to be used should be determined based on the network's data transmission needs and investment quotas. Note that not all optical fiber transceiver supports full duplex, and some products only support half duplex. Therefore, you should pay attention to identification during the purchase. In addition, considering compatibility, we recommend that you use products of the same brand and type.

One end of the optical transceiver is connected to the optical distribution frame using a fiber jumper to connect to the remote optical interface. The other end is connected to the RJ-45 port of the switch using a twisted pair jumper, connect to other computers on the vswitch to complete the optical fiber transmission of the network backbone.

When the diameter of the network is too large and the transmission distance is far beyond the distance supported by twisted pair wires, the network will be transmitted through optical fiber. If the network user competition is less, just to achieve long-distance communication, the network performance and data transmission rate is not too high, you can use the photoelectric transceiver + common RJ-45 port switch at both ends of the way, this significantly reduces network costs. The connection method 2 of the network device is shown in.

Figure 2 optical transceiver is used at both ends of the high-end switch Cascade

If the network is connected to multiple buildings with high requirements for data transmission performance, but a subnet does not require high performance, you can only use the optical transceiver at one end, the other end uses a central or backbone switch with an optical fiber interface to ensure the overall network performance while improving the cost-effectiveness of the network.

When connecting the optical transceiver and the switch, you should pay attention to the following issues in the cascade of high-end switches:

◆ The twisted pair jumper connecting the optical transceiver and the switch should be a straight line. Some Optical Transceiver provides an MDI/MDI-X button switch that is required to press the MDI/MDI-X switch button when cross wires are used, without pressing this button. In fact, as long as the LED turns green, it is connected. Otherwise, there is a problem with the connection jumper or the switch button.

◆ Optical Fiber jumper connecting the optical transceiver and the optical fiber distribution frame is usually a ST-SC, the SC end is connected to the optical transceiver, the ST end is connected to the optical fiber distribution frame.

◆ The type and core diameter of the optical jumper must be exactly the same as the optical fiber used in the cabling.

Redundant connection and Its Implementation

No matter what equipment is, it cannot guarantee the absolute stability of operation, even if it is a good product, it cannot guarantee 24 × 7 uninterrupted work. In addition to hardware faults such as device or module damage and transmission line interruption, the core switch may be paralyzed due to network traffic overload and excessive task load.

Therefore, to ensure the stability of the network and ensure that important services are not interrupted, necessary countermeasures must be taken. In general, this is a redundant connection, that is, creating multiple connections between the core switch and the backbone switch, and between the switch and the server.

High-end switch cascade EtherChannel

EtherChannel and Port Trunking multi-trunk redundant connections) technology. multiple ports on the switch are physically connected and logically bundled to form a Port with a large bandwidth, A trunk channel can be formed to increase the connection bandwidth between switches and servers, achieve load balancing and provide redundant connections.

When all ports work normally, the bound bandwidth is the sum of the bandwidth of all ports. When a port goes down, other ports can still maintain normal connections. Cisco's EtherChannel has two levels: Fast EtherChannel and Giga Etherchannel. The maximum bandwidth is Mbps and 4 Gbps, respectively.

High-end switch cascade Spanning Tree

The Spanning Tree implements redundant connections in the form of Stand. Create two links between vswitches. Because there are two links between vswitches, this will lead to topology ring 3). Therefore, with the help of the Spanning Tree technology, apart from one link, other links are actually in the standby Stand By status, which obviously affects the transmission efficiency.

Figure 3 topology ring caused by redundant connections