Expose switch TRUNK configuration problems

TRUNKAs an important indicator, it is often mentioned in the performance parameters of L2 switches. Many L2 Switch products will mention that they can support the TRUNK function when introducing its performance, this can provide better Transmission Performance Between Interconnected switches. Here is the introduction of TRUNK.

1. What is TRUNK?

TRUNK indicates port aggregation, that is, by configuring the software settings, combine two or more physical ports into one logical path to increase the bandwidth between the vswitch and the network node, and merge the bandwidth of these ports.

The port is provided with a high bandwidth that is several times the exclusive bandwidth of the Independent Port. Trunk is a encapsulation technology. It is a point-to-point link. both ends of the link can be a switch, a switch, a router, or a host, a switch, or a router. Based on the port aggregation Trunk) function.

Allows a vswitch and vswitch, vswitch and vro, and host and vswitch or vro to communicate with each other through two or more ports simultaneously to provide higher bandwidth and higher throughput, greatly providing the overall network capability. Generally.

When TRUNK is not used, we all know that this transmission media feature of the 10/100 M Ethernet twisted pair determines that the bandwidth of the two common 100 switches is only M, if the full duplex mode is used, the maximum bandwidth for transmission can reach 200 MB.

In this way, the network trunk and server bottlenecks are formed. To achieve a higher data transmission rate, you need to change the transmission media, use a gigabit optical fiber or upgrade to a Gigabit Ethernet, although the bandwidth can reach a Gigabit, however, the cost is very expensive, and the switch may need to be replaced ).

It is not suitable for low-cost SMEs and schools. If the TRUNK technology is used, four ports are bundled together to achieve mbps bandwidth, which can better solve the contradiction between cost and performance.

II. Specific Application of TRUNK

TRUNK port aggregation) is a relatively economical method to increase bandwidth between a vswitch and a network device, such as a server, router, workstation, or other vswitch. The method to increase the bandwidth is effective when the connection between a single switch and a node cannot meet the load.

The main function of TRUNK is to bind multiple physical ports to a logical channel, which works like a channel. After multiple physical links are bound together, not only the bandwidth of the entire network is increased, but the data can also be

The transmission of multiple bound physical links has the function of link redundancy. When one or more links are disconnected due to network faults or other causes, the remaining links can work. However, in VLAN data transmission, different manufacturers use different technologies, such as Cisco products.

With its vlan trunk technology, most of the products of other vendors support the 802.1q protocol to add a TAG header, which generates a small giant frame and needs to be identified using the same port protocol, because the size of a giant frame exceeds the 1518-byte limit of the standard ethereum frame, the common Nic cannot recognize the frame and requires a switch to untag it.

Precautions for switch TRUNK Configuration

In a TRUNK, data is always from a specific source point to a destination point, and a single link is designed to process broadcast packets or uncertain packets. When configuring TRUNK, you must follow the following rules:

1: correctly select the number of TRUNK ports, which must be 2, 4 or 8.

2: the ports in the same group must be used. The ports on the vswitch are divided into several groups. All ports of the TRUNK must come from the same group.

3: Use Continuous ports. The ports on the TRUNK must be continuous. For example, you can combine ports, 6, and 7 into a port aggregation.

4: generate only one TRUNK in a group of ports.

The contents of TRUNK have been introduced to you. We hope that the above analysis can help you understand TRUNK.