4.3 Configuring VLANs
4.3.2 Verify VLAN configuration
As shown in Figure , it is considered to be good practice to verify your VLAN configuration by using the show vlan command while in privileged mode. The output example from a Cisco IOS command-based switch shows that VLAN 2 is configured on module 0, port 3.

The output example from a set command-based switch in Figure shows that VLAN 1 is configured on Module 1, Ports 1 and 2; VLAN 10 is configured on Module 2, Ports 1 through 10; and VLAN 20 is configured on Module 2, Ports 11 through 24.

The following facts should be remembered:

  • A created VLAN remains unused until it is mapped to switch ports. Use the set vlan command to map VLANs to ports.
  • The default configuration has all Ethernet ports on VLAN 1. However, you can enter groups of ports as individual entries, for example, 2/1, 3/3, 3/4, or 3/5. You can also use a hyphenated format to map multiple ports, for example, 2/1-4 or 3/3-5.
  • Do not enter spaces between the port numbers. The switch will give you an error message because a space delimits another argument that is not in the command structure of this command.
Interactive Lab Activity  (Flash, 390 kB)
  In this activity, you will learn how to configure and verify VLAN's on a Catalyst 4000 switch.
Interactive Lab Activity  (Flash, 380 kB)
  In this activity, you will learn how to configure and verify VLAN's on a Catalyst 2900 switch.