System information

VLAN Commands
4-141
Command Mode
Interface Configuration (Ethernet, Port Channel)
Command Usage
• A port, or a trunk with switchport mode set to hybrid, must be assigned to
at least one VLAN as untagged.
• If a trunk has switchport mode set to trunk (i.e., 1Q Trunk), then you can
only assign an interface to VLAN groups as a tagged member.
• Frames are always tagged within the switch. The tagged/untagged
parameter used when adding a VLAN to an interface tells the switch
whether to keep or remove the tag from a frame on egress.
• If none of the intermediate network devices nor the host at the other end of
the connection supports VLANs, the interface should be added to these
VLANs as an untagged member. Otherwise, it is only necessary to add at
most one VLAN as untagged, and this should correspond to the native
VLAN for the interface.
• If a VLAN on the forbidden list for an interface is manually added to that
interface, the VLAN is automatically removed from the forbidden list for that
interface.
Example
The following example shows how to add VLANs 1, 2, 5 and 6 to the allowed list as
tagged VLANs for port 1:
Displaying VLAN Information
show vlan
This command shows VLAN information.
Syntax
show vlan [id vlan-id | name vlan-name]
• id - Keyword to be followed by the VLAN ID.
vlan-id - ID of the configured VLAN. (Range: 1-4094, no leading zeroes)
• name - Keyword to be followed by the VLAN name.
vlan-name - ASCII string from 1 to 32 characters.
Console(config)#interface ethernet 1/1
Console(config-if)#switchport allowed vlan add 1,2,5,6 tagged
Console(config-if)#
Command Function Mode Page
show vlan Shows VLAN information NE, PE 4-141
show interfaces status vlan Displays status for the specified VLAN interface NE, PE 4-93
show interfaces switchport Displays the administrative and operational status of an
interface
NE, PE 4-95