Chapter 13 Configuring VLANs

Configuring VLAN Trunks

Beginning in privileged EXEC mode, follow these steps to remove VLANs from the pruning-eligible list on a trunk port:

 

Command

Purpose

Step 1

 

 

configure terminal

Enter global configuration mode.

Step 2

 

 

interface interface-id

Select the trunk port for which VLANs should be pruned, and enter

 

 

interface configuration mode.

Step 3

 

 

switchport trunk pruning vlan {add

Configure the list of VLANs allowed to be pruned from the trunk. (See

 

except none remove} vlan-list

the “VTP Pruning” section on page 14-4).

 

[,vlan[,vlan[,,,]]

For explanations about using the add, except, none, and remove

 

 

 

 

keywords, see the command reference for this release.

 

 

Separate nonconsecutive VLAN IDs with a comma and no spaces; use a

 

 

hyphen to designate a range of IDs. Valid IDs are 2 to 1001.

 

 

Extended-range VLANs (VLAN IDs 1006 to 4094) cannot be pruned.

 

 

VLANs that are pruning-ineligible receive flooded traffic.

 

 

The default list of VLANs allowed to be pruned contains VLANs 2 to

 

 

1001.

Step 4

 

 

end

Return to privileged EXEC mode.

 

 

 

Step 5 show interfaces interface-idswitchport

Verify your entries in the Pruning VLANs Enabled field of the display.

Step 6

 

 

copy running-config startup-config

(Optional) Save your entries in the configuration file.

 

 

 

To return to the default pruning-eligible list of all VLANs, use the no switchport trunk pruning vlan interface configuration command.

Configuring the Native VLAN for Untagged Traffic

A trunk port configured with IEEE 802.1Q tagging can receive both tagged and untagged traffic. By default, the switch forwards untagged traffic in the native VLAN configured for the port. The native VLAN is VLAN 1 by default.

Note The native VLAN can be assigned any VLAN ID.

For information about IEEE 802.1Q configuration issues, see the “IEEE 802.1Q Configuration Considerations” section on page 13-19.

Beginning in privileged EXEC mode, follow these steps to configure the native VLAN on an

IEEE 802.1Q trunk:

 

Command

Purpose

Step 1

 

 

configure terminal

Enter global configuration mode.

Step 2

 

 

interface interface-id

Define the interface that is configured as the IEEE 802.1Q trunk, and

 

 

enter interface configuration mode.

 

 

 

 

 

Catalyst 3750-E and 3560-E Switch Software Configuration Guide

 

 

 

 

 

 

OL-9775-02

 

 

13-23

 

 

 

 

 

Page 367
Image 367
Cisco Systems 3750E Configuring the Native Vlan for Untagged Traffic, Switchport trunk pruning vlan add, Vlan ,vlan, 13-23