What is a VLAN?

A VLAN divides one physical switched network into separate logical broadcast domains.

enable
configure terminal
vlan 10
 name STUDENTS
vlan 20
 name STAFF
interface gigabitEthernet 0/1
 switchport mode access
 switchport access vlan 10
interface gigabitEthernet 0/24
 switchport mode trunk
end
show vlan brief
show interfaces trunk

Commands vary by device model and IOS version. Verify the allowed VLAN list on trunks.

Practice

Create two VLANs in Packet Tracer, assign access ports and configure a trunk between two switches.