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Catalyst2950 and Catalyst2955 Switch Software Configuration Guide
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Chapter17 Configuring VLANs
Configuring VLAN Trunks
To return to the default allowed VLAN list of all VLANs, use the no switchport trunk allowed vlan
interface configuration command.
This example shows how to remove VLAN 2 from the allowed VLAN list:
Switch(config)# interface fastethernet0/1
Switch(config-if)# switchport trunk allowed vlan remove 2
Switch(config-if)# end
Switch#
Changing the Pruning-Eligible List
The pruning-eligible list applies only to trunk ports. Each trunk port has its own eligibility list. VTP
pruning must be enabled for this procedure to take effect. The “Ena bling VTP Pruning” section on
page 18-14 describes how to enable VTP pruning.
Beginning in privileged EXEC mode, follow these steps to remove VLANs from the pruning-el igible list
on a trunk port:
Step4 switchport trunk allowed vlan {add |
all | except | remove} vlan-list (Optional) Configure the list of VLANs allowed on the trunk.
For explanations about using the add, all, except, and remove keywords,
refer to the command reference for this releas e.
The vlan-list parameter is either a single VLAN number from 1 to 4094
when the EI is installed, and 1 to 1005 when the SI is installed or a range
of VLANs described by two VLAN numbers, the lower one first,
separated by a hyphen. Do not enter any spaces between
comma-separated VLAN parameters or in hyphen-specified ranges.
All VLANs are allowed by default.
Step5 end Return to privileged EXEC mode.
Step6 show interfaces interface-id switchport Verify your entries in the Trunking VLANs Enabled field of the display.
Step7 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 interface interface-id Enter interface configuration mode, and select the trunk port for which
VLANs should be pruned.
Step3 switchport trunk pruning vlan {add |
except | none | remove} vlan-list
[,vlan[,vlan[,,,]]
Configure the list of VLANs allowed to be pruned from the trunk. (See
the “VTP Pruning” section on page 18-4).
For explanations about using the add, except, none, and remove
keywords, refer to 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 from 2 to 1001.
Extended-range VLANs (VLAN IDs 1006 to 4094) cannot be p run ed .
VLANs that are pruning-ineligible receive flooded traffic.
The default list of VLANs allowed to be pruned contains VLANs 2 to
1001.