Detailed explanation of the TRUNK configuration function of the core switch

What is the TRUNK of the core switch? What application advantages can TRUNK bring to us? How to configure the TRUNK in a specific switch product? Let's take a look at these knowledge. An important indicator is often mentioned in the performance parameters of L2 switches: TRUNK. Many L2 Switch products will mention that it can support the TRUNK function when introducing its performance, this can provide better Transmission Performance Between Interconnected switches. So what is TRUNK? What application advantages can TRUNK bring to us? In addition, how to configure the TRUNK in a specific switch product. Let's take a look at these knowledge. 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 the TRUNK is not used at www.2cto.com, we all know that the transmission media feature of the 10/100 M Ethernet twisted pair determines that the bandwidth of the two interconnected common 100 switches is only M, if the full duplex mode is used, the maximum bandwidth for transmission can reach 200 MB, which forms a network trunk and server bottleneck. 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, but the cost is very expensive (maybe even a switch needs to be replaced), which is more uncomfortable? A href =" http://www.bkjia.com/os/ "Target =" _ blank "class =" keylink "> the system will kill the camera with the Yunxiao Island and take off the J branch, H Branch, and other RUNK technology, bind the four ports together to achieve mbps bandwidth, which can better solve the contradiction between cost and performance. 2. The specific application of TRUNK (Port aggregation) is a relatively economical method to increase bandwidth between the switch and network equipment, such as servers, routers, workstation or other switches. 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 (generally 2-8) to a logical channel to make it work like a channel. Bundling multiple physical links not only improves the bandwidth of the entire network, but also data can be transmitted through multiple bound physical links at the same time, which has the function of link redundancy, when one or more links are disconnected due to network faults or other causes, the remaining links can still work. However, in VLAN data transmission, different manufacturers use different technologies. For example, Cisco products use vlan trunk technology. Most products of other manufacturers support the 802.1q protocol with the TAG header, in this way, a small giant frame is generated and must be identified using the same port protocol. Because the size of a small giant frame exceeds the 1518-byte limit of the standard Ethernet frame, it cannot be identified by a common Nic and requires a switch to remove the TAG. The TRUNK function is suitable for the following applications: 1. The TRUNK function is used to connect to the server and provide the server with an exclusive high bandwidth. 2. The TRUNK function is used for cascade between switches. It sacrifices the number of ports to provide bundled high bandwidth for data exchange between switches, improving network speed and breaking through network bottlenecks, this greatly improves network performance. 3. Trunk can provide load balancing capabilities and system fault tolerance. As Trunk balances the traffic of each switch port and server interface in real time, once a port fails, it will automatically remove the faulty port from the Trunk group, and then re-allocate the traffic of each Trunk port, so as to realize system fault tolerance. 3. How to configure TRUNK? To set the TRUNK, you must specify a port as the Trunk, for example, 2/24. To set a port to the TRUNK mode, run the following command: set trunk mod/port [on | off | desirable | auto | nonegotiate] [vlan_range] [isl | dot1q dot10 | lane | negotiate]. Www.2cto.com the command can be divided into four parts: mod/port: Specify the port on which the user wants to run Trunk; the running mode of Trunk, which includes: on | off | desirable | auto | nonegotiate. To automatically identify the Trunk over fast Ethernet and Gigabit Ethernet, you must ensure that the Trunk is in the same VTP domain. You can also use the On or Nonegotiate mode to force a Trunk On a port, regardless of whether it is in the same VTP domain. VLAN range. The default value is 1 ~ 1005, which can be modified, but must have the TRUNK protocol. When TRUNK is used, the protocol on the adjacent ports must be consistent. In addition, you need to set the port connected to the following switch to TRUNK on the central switch, so that multiple VLANs in the following switch can communicate with the central switch through one link. 4. Precautions for configuring TRUNK: in a TRUNK, data is always directed from a specific source point to the destination point, 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. This article is from the fat shark network.