Secrets: how to configure Virtual LAN VLAN

Secrets: how to configure a VLAN on a vswitch When configuring a VLAN in a virtual LAN, I will introduce the VLAN configuration in the article, we will provide you with a learning direction for relevant knowledge.

We know that the 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. 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. Let's take a look at it.

It indicates that departments of the same nature in the two floors are divided into one VLAN. In this way, the accounting data will not be broadcast to the machines on the market or conflict with the machines on the market. Therefore, VLAN effectively separates conflicting domains and broadcast domains. We can define VLANs on a port of a vswitch. All terminals connected to this specific port are part of the virtual network, and the entire network can support multiple VLANs.

The Virtual lan vlan is configured to minimize unnecessary data traffic by establishing a network firewall, isolating the transmission between VLANs and possible problems, greatly increasing the network throughput and reducing network latency. In a virtual network environment, you can divide different virtual networks to control the communication between users in the same physical network segment.

In this way, data confidentiality is effectively realized, and configuration is not troublesome. The network administrator can logically reconfigure the network to quickly, easily, and effectively balance load traffic, you can easily add, delete, and modify users without physically adjusting network configurations.

Since VLAN has so many advantages, why don't we understand it and apply VLAN configuration technology to our real-world network management. Let's use the actual example of configuring static vlan on the ipvst1900 switch to see how to configure a virtual lan vlan on the switch. After the Super Terminal is configured and the 1900 switch is connected, the following main configuration page is displayed:
1 user (s) nowactiveonManagementConsole.
UserInterfaceMenu
[M] Menus
[K] CommandLine
IPConfiguration
EnterSelection:

We will briefly introduce the three options shown here. [M] Menus is the main menu, mainly the initial configuration of the switch and monitoring the running status of the switch. [K] CommandLine is a command line. Like using commands in a vro to configure and monitor a vro, it mainly uses commands. IPConfiguration is an option for configuring IP addresses, subnet masks, and default network management.

This is the first time the switch is connected. If you have configured IPConfiguration, this option will not be available for the next login. Because the command configuration is concise, clear, and easy to understand, we use [K] CommandLine to configure Virtual LAN VLANs. After the Super Terminal is configured and the 1900 switch is connected, the following main configuration page is displayed:
1 user (s) nowactiveonManagementConsole.
UserInterfaceMenu
[M] Menus
[K] CommandLine
IPConfiguration
EnterSelection:

We will briefly introduce the three options shown here. [M] Menus is the main menu, mainly the initial configuration of the switch and monitoring the running status of the switch. [K] CommandLine is a command line. Like using commands in a vro to configure and monitor a vro, it mainly uses commands. IPConfiguration is an option for configuring IP addresses, subnet masks, and default network management.

This is the first time the switch is connected. If you have configured IPConfiguration, this option will not be available for the next login. Because the command configuration is concise, clear, and easy to understand, we use [K] CommandLine to configure Virtual LAN VLANs. Select [K] CommandLine to go to the command line Configuration:
EnterSelection: K press ENTER
CLIsessionwiththeswitchisopen.
ToendtheCLIsession, enter [Exit].>

Now we enter the common user mode of the vswitch, just like a vro. In this mode, we can only view the current configuration, but cannot change the configuration, and the commands that can be used are very limited. We enter enable to enter the privileged mode:
> Enable
# Configt
Enterconfigurationcommands, oneperline. EndwithCNTL/Z
(Config )#

For security and convenience, we should name the vswitch and set the login password.
(Config) # hostname1900Switch
1900 Switch (config) # enablepasswordlevel15goodwork
1900 Switch (config )#

Note: The password must be 4-8 characters long. The vswitch password is slightly different from the vro. The vswitch uses the level to determine the password permission. Level1 is the password used to access the command line interface. That is to say, after setting the level1 password, you will be asked to enter the password next time you connect to the switch and enter K, this password is the password set by level1. Level15 is the privileged mode password that you enter after you enter the enable command. Enablepassword and enablescreet are used in the vro to distinguish between them. Well, we have already set the name and password to ensure security. Let's set the VLAN.