VLAN
VLAN means virtual local area network.Vlans are used to separate multiple networks while being on the same physical network.
View existing Vlans :
router(config)#show vlan
Configuring a Vlan:
router(config) #configure terminal
router(config)#vlan
router(config)#interface range gigabitEthernet 1/0/2-6
router(config)#switchport access vlan
router(config)#exit
Removing a Vlan:
In order to remove a vlan first, assign the ports on the vlan to default vlan which is vlan 1
router #configure terminal
router(config) #interface range gigabitEthernet 1/0/2-6
router(config)#switchport access vlan 1
router(config)#no vlan