Expert Consultation: in-depth understanding of VLan configuration

Bkjia.com Expert Clinic is a special topic on the BKJIA website. Each session has a subject and an expert. It aims to provide a timely and convenient communication platform for the majority of users, as soon as the topic was launched, it was well received by a large number of network engineers. The discussion on the topic was very enthusiastic.

The topic "in-depth understanding of VLan configuration" recently discussed has an unprecedented atmosphere. This is because Mr. Yu, the information system director of the eastern homeland, was invited. In addition to his rich experience in VLAN configuration, Mr. Yu is also tired of asking questions from netizens!

For new friends in the Network management industry, it is not clear about the benefits of VLAN and VLAN. Mr. Yu answered, "VLAN is short for Virtual Local Area Network, the Chinese name is "Virtual LAN", and VLAN is a way to divide LAN devices logically. Note that VLAN is not physically divided into network segments or smaller LAN segments ), data Exchange Technology for virtual workgroup units. Its main function is to avoid broadcast storms and improve network efficiency ." "What kind of network requires VLAN division?" Mr. Yu said, "when the network reaches a certain scale, many devices should use VLAN when facing a lot of network communication difficulties in a LAN. The specific situation depends on the actual situation, such as the number of hosts, routing switch devices, and investment funds ."

Years of network experience and experience

In addition to asking technical questions about Mr. Yu, a netizen also asked some experience and personal feelings. Mr. Yu also gave a generous answer without reservation. The netizen said this: "You have been engaged in the company's network planning, Interconnection Implementation, and maintenance work to maintain the normal operation of business on the company's network. The main task is to lead the team to complete the upgrade and transformation of the entire network. I have senior practical experience in vlan division. Can you tell me more about your understanding of VLANs ?"
Traditional LAN Ethernet adopts the CSMA/CD method with conflict detection. In the CSMA/CD network, nodes can use the network whenever they have data to be sent. Before a node transmits data, it performs a "listener" to check whether the network is busy. If not, the node starts to transmit data. If the network is in use, the node waits. If the two nodes do not hear anything and start to use the line at the same time, a conflict will occur. When sending data, if it uses a broadcast address, all the PCs in this network segment will receive data packets, so that if there are many PCs in this network segment, it is easy to cause a broadcast storm. Conflicts and broadcast storms are important factors affecting network performance. To solve this problem, the concept of virtual lan vlan is introduced.
A virtual network is a virtual working group established by a network switching device in the entire network. The virtual network is logically equal to the Layer 2 broadcast domain of the OSI model, and has nothing to do with the specific physical network and geographical location. Virtual workgroup can contain departments and working groups in different locations, without the need to reconfigure any ports physically, truly implementing network users and their physical
A virtual network is a virtual working group established by a network switching device in the entire network. The virtual network is logically equal to the Layer 2 broadcast domain of the OSI model, and has nothing to do with the specific physical network and geographical location. A virtual workgroup can contain departments and working groups in different locations, without having to reconfigure any ports physically, thus realizing that network users are not related to their physical locations. The Virtual Network Technology divides traditional broadcast domains into independent sub-broadcast domains as needed, and limits broadcast in virtual working groups. Due to the narrowing of the broadcast domains, the proportion of bandwidth consumed by broadcast packets in the network is greatly reduced, and the network performance is significantly improved.
I divided the network of our headquarters into about 10 VLANs. The Division principle is to combine the floor and department considerations. VLAN Division ensures the normal operation of the entire network, network Fault Locating and troubleshooting time is greatly shortened, improving network performance. It also facilitates the implementation of DHCP, traffic monitoring, and other management methods.

The meeting ended with a question. Due to the time relationship, the expert's outpatient activities ended, and questions left unanswered, the experts will continue to answer questions for the netizens.

Expert introduction:
Yu
Currently, the information center system support department director of ORIENTHOME is in charge of 25 large stores in China. All stores are connected to the Beijing headquarters through a 2 m leased line, all of the company's network interconnection uses CISCO switches and routers. After entering Dongfang jiayuan Co., Ltd. at the end of 98, he has been engaged in network planning, Interconnection Implementation, and maintenance to maintain the normal operation of business on the enterprise's network, the main task is to lead the team to complete the upgrade and transformation of the entire network.

For more information, see Vlan configuration for network channels.