Defining The Allowed Vlans On A Trunk - Cisco Catalyst 2960 series Configuration Manual

Configuring VLAN Trunks
Related Topics
Trunking Modes, on page 60
Layer 2 Interface Modes, on page 60

Defining the Allowed VLANs on a Trunk

VLAN 1 is the default VLAN on all trunk ports in all Cisco switches, and it has previously been a requirement
that VLAN 1 always be enabled on every trunk link. You can use the VLAN 1 minimization feature to disable
VLAN 1 on any individual VLAN trunk link so that no user traffic (including spanning-tree advertisements)
is sent or received on VLAN 1.
SUMMARY STEPS
1. configure terminal
2. interface interface-id
3. switchport mode trunk
4. switchport trunk allowed vlan {add | all | except | remove} vlan-list
5. end
6. show interfaces interface-id switchport
7. copy running-config startup-config
DETAILED STEPS
Command or Action
Step 1
configure terminal
Example:
Switch# configure terminal
Step 2 interface interface-id
Example:
Switch(config)# interface gigabitethernet1/0/1
Step 3
switchport mode trunk
Example:
Switch(config-if)# switchport mode trunk
Step 4 switchport trunk allowed vlan {add | all | except |
remove} vlan-list
OL-29065
Purpose
Enters the global configuration mode.
Specifies the port to be configured, and enters interface
configuration mode.
Configures the interface as a VLAN trunk port.
(Optional) Configures the list of VLANs allowed on the trunk.
The vlan-list parameter is either a single VLAN number from
1 to 4094 or a range of VLANs described by two VLAN
Catalyst 2960-X Switch VLAN Configuration Guide, Cisco IOS Release 15.0(2)EX
Configuring an Ethernet Interface as a Trunk Port
67