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Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 13 Configuring VLANs, VTP, and VMPS VLAN Trunking Protocol
Because Layer 3 ports and some software features require internal VLANs allocated from 1006 and
up, configure extended-range VLANs starting with 4094 and work downward.
You can configure extended-range VLANs only in global configuration mode. You cannot
configure extended-range VLANs in VLAN database mode.
Layer 3 ports and some software features use extended-range VLANs. If the VLAN you are trying
to create or modify is being used by a Layer 3 port or a software feature, the switch displays a
message and does not modify the VLAN configuration.
When you create VLANs with the VLAN configuration command, they are automatically added to
the existing VTP domain; no action is required of the user.
This example shows how to create an Ethernet VLAN in global configuration mode and verify the
configuration:
Switch# configure terminal
Switch(config)# vlan 3
Switch(config-vlan)# end
Switch# show vlan id 3
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
3 VLAN0003 active
VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
3 enet 100003 1500 - - - - - 0 0
Primary Secondary Type Interfaces
------- --------- ----------------- -------------------------------------------
Switch#

Assigning a Layer 2 LAN Interface to a VLAN

A VLAN created in a management domain remains unused until you assign one or more LAN interfaces
to the VLAN.
Note Make sure you assign LAN interfaces to a VLAN of the proper type. Assign Fast Ethernet, Gigabit
Ethernet, and 10-Gigabit Ethernet interfaces to Ethernet-type VLANs.
To assign one or more LAN interfaces to a VLAN, complete the procedures in the “Configuring Ethernet
Interfaces for Layer 2 Switching” section on page 15-5.
VLAN Trunking Protocol
This section describes the VLAN Trunking Protocol (VTP) on the Catalyst 4500 series switches, and
includes the following major subsections:
About VTP, page 13-8
VTP Configuration Guidelines and Restrictions, page 13-12
VTP Default Configuration, page 13-13
Configuring VTP, page 13-14