You may use the following method to configure Virtual LANs (VLANs) on a Cisco Catalyst 3560 switch. VLANs allow you to segment a layer 2 switched network by increasing the number of layer 2 broadcast domains and decreasing their size. Additionally, VLANs provide an added measure of network security.
Begin by entering global configuration mode with the configure terminal command.
Next, use the vlan # command where the # sign is the number of the VLAN. Additionally, use the name “name” command to provide a custom description of the VLAN. In this example there are three created VLANS, 2 (Sales), 3 (Marketing) and 4 (Accounting).
Lastly, you may verify the creation of the VLANs with the show vlan command.