Reference Guide

To activate the VLAN, after you create a VLAN, assign interfaces in Layer 2 mode to the VLAN.
To view the configured VLANs, use the show vlan command in EXEC Privilege mode.
Example of Verifying a Port-Based VLAN
FTOS#show vlan
Codes: * - Default VLAN, G - GVRP VLANs
NUM Status Q Ports
* 1 Inactive U So 9/4-11
2 Active U Gi 0/1,18
3 Active U Gi 0/2,19
4 Active T Gi 0/3,20
5 Active U Po 1
6 Active U Gi 0/12
U So 9/0
FTOS#
Assigning Interfaces to a VLAN
You can only assign interfaces in Layer 2 mode to a VLAN using the tagged and untagged commands. To place an
interface in Layer 2 mode, use the
switchport command.
You can further designate these Layer 2 interfaces as tagged or untagged. For more information, refer to the Interfaces
chapter and Configuring Layer 2 (Data Link) Mode. When you place an interface in Layer 2 mode by the switchport
command, the interface is automatically designated untagged and placed in the Default VLAN.
To view which interfaces are tagged or untagged and to which VLAN they belong, use the show vlan command. The
following example shows that six VLANs are configured, and two interfaces are assigned to VLAN 2. The Q column in
the show vlan command example notes whether the interface is tagged (T) or untagged (U). For more information
about this command, refer to the Layer 2 chapter of the
FTOS Command Reference Guide .
To tag frames leaving an interface in Layer 2 mode, assign that interface to a port-based VLAN to tag it with that VLAN
ID. To tag interfaces, use the following commands.
1. Access INTERFACE VLAN mode of the VLAN to which you want to assign the interface.
CONFIGURATION mode
interface vlan vlan-id
2. Enable an interface to include the IEEE 802.1Q tag header.
INTERFACE mode
tagged interface
To view just the interfaces that are in Layer 2 mode, use the show interfaces switchport command in EXEC
Privilege mode or EXEC mode.
The following example shows the steps to add a tagged interface (in this case, port channel 1) to VLAN 4. To view the
interface’s status. Interface (po 1) is tagged and in VLAN 2 and 3, use the show vlan command. In a port-based VLAN,
use the tagged command to add the interface to another VLAN. The show vlan command output displays the
interface’s (po 1) changed status.
Except for hybrid ports, only a tagged interface can be a member of multiple VLANs. You can assign hybrid ports to two
VLANs if the port is untagged in one VLAN and tagged in all others.
Add an Interface to Another VLAN
FTOS#show vlan
Codes: * - Default VLAN, G - GVRP VLANs
704