Cisco iOS Basics: VLANs

Every Cisco switch (and router) has VLAN 1 on it by default. VLANs (or Virtual Local Area Network)
One switch can have multiple VLANs that connects to different network.

For example, networks 10.10.20.0, 10.10.30.0 and 10.10.40.0 can on reside on the same switch thanks to VLANs.

You can check VLANs on your switch with following command

Zeljko#show vlan

CiscoVLANsCreation

I will now create new VLAN (20) and assign port FA0/1-FA0/4 to that VLAN

Zeljko(config)#vlan 20
Zeljko(config-vlan)#exit
Zeljko(config)#interface range fastethernet 0/1 – 4
Zeljko(config-if-range)#switchport mode access
Zeljko(config-if-range)#switchport access vlan 20
Zeljko(config-if-range)#exit
CiscoVLANsCreation1

Lets check results

Zeljko#show vlan

CiscoVLANsCreation2

Success

If you want to delete VLAN, it’s pretty simple

I’ll use created VLAN 20 and assigned ports for demonstration

First I need to remove assigned ports to VLAN 20. I’ll move them back to VLAN 1

Zeljko(config)#interface range fastethernet 0/1 – 4
Zeljko(config-if-range)#switchport mode access
Zeljko(config-if-range)#switchport access vlan 1

After that I’ll remove VLAN 20

Zeljko(config)#no vlan 20

If you check with Zeljko#show vlan , all ports are back to VLAN 1 and VLAN 20 is deleted.

Disclaimer