How to Create and Delete VLAN on Cisco Catalyst Switch?

Virtual Local Area Networks (VLANs) are used in computer networks to divide a physical network into many logical networks, enhancing security, flexibility, and scalability. This article will walk you through the steps of adding and removing VLANs from a Cisco Catalyst Switch.

Steps To Create and Delete VLAN on Cisco Catalyst Switch

Step 1: Open the Command Line Interface (CLI) of the Switch. You must use the Cisco Catalyst Switch’s Command Line Interface to setup VLANs. This may be accomplished with a console cable or remotely using Telnet or SSH.

Step 2: Enter Privileged EXEC Mode. Once you’ve accessed the CLI, enter privileged EXEC mode by running the following command and entering the necessary password:

switch> enable

Step 3: Navigate to the Global Configuration Mode. Type the following command to enter global configuration mode:

switch# configure terminal

Step 4: Create a VLAN.Use the following command to create a VLAN:

switch(config)# vlan ‘<vlan_id>’

Substitute <vlan_id> with the required VLAN number. For instance, to create VLAN 10, enter:

switch(config)# vlan 10

Step 5: Copy the code switch(config)# vlan 10. Give the VLAN a name. Use the following command to give the VLAN a descriptive name:

switch(config-vlan)# name <vlan_name>

Substitute <vlan_name> with required name. As an example:

switch(config-vlan)# name Sales

Step 6: VLAN Interface Configuration (Optional). You can construct a VLAN interface if you wish the VLAN to have Layer 3 capabilities. The following command should be used:

switch(config)# interface vlan ‘<vlan_id>’

<vlan_id> should be replaced with the VLAN number you want to setup. To configure VLAN 10, for example, use:

Switch(config)# vlan 10 interface

Then, using the ip address command, assign an IP address to the VLAN interface.

Step 7: Assign the VLAN’s ports. Use the following command to add ports to the VLAN.

switch(config)# interface ‘<interface_id>’

Replace ‘<interface_id>’ with the name of the VLAN interface you wish to attach. To attach interface FastEthernet 0/1 to VLAN 10, for example, use:

Switch(config)# interface FastEthernet 0/1

Switch(config-if)# access switchport mode

Switch(config-if)# access switchport vlan 10

Step 8: Check the Configuration. Use the following commands to confirm that the VLAN has been formed and the ports have been appropriately assigned:

switch# show vlan

switch# show interfaces switchport

These commands will display the VLAN information as well as the interface status.

Step 9:For Delete a VLAN use the following command.

switch(config)# no vlan <vlan_id>

Replace ‘< vlan_id>’ with the VLAN number to be removed. To remove VLAN 10, for example, type:

switch(config)# no vlan 10

Different Approaches To VLANs

• VLAN Trunking Protocol (VTP): VTP enables automated VLAN configuration dissemination across numerous network switches.
• VLAN Routing: VLAN routing is the process of routing traffic between VLANs utilising Layer 3 switches or routers.
• VLAN Security: By separating critical resources and instituting access control, VLANs may be utilised to improve network security.

Applications of VLAN

1. Network Segmentation: VLANs offer network segmentation, allowing distinct departments or projects to have their own isolated network environments.
2. Broadcast Control: VLANs limit the scope of broadcast traffic, which reduces network congestion and improves overall performance.

Advantages of VLAN

1. Security: VLANs can segregate critical data, restricting unauthorised access and decreasing the attack surface.
2. Improved Network Performance: VLAN segmentation minimises broadcast traffic, which improves network performance.
3. Scalability: VLANs provide flexible network growth without requiring physical reconfiguration.

Disadvantages of VLAN

1. Complexity: Configuring and administering VLANs may be difficult, necessitating networking knowledge and careful planning.
2. Administrative Overhead Increased: VLANs may need greater administrative work for maintenance, monitoring, and troubleshooting.
3. Limited Broadcast Domain:A tiny broadcast domain might get saturated if VLANs are not appropriately constructed, reducing network performance.

Conclusion

Creating and removing VLANs on a Cisco Catalyst Switch is a critical network management operation. You can efficiently manage VLANs to optimise network performance and security by following the step-by-step guidance and learning the fundamentals, subtopics, applications, benefits, and drawbacks.