Switchport Trunk - Cisco Catalyst 2950 Command Reference Manual

switchport trunk

switchport trunk
Use the switchport trunk interface configuration command to set the trunk characteristics when the
interface is in trunking mode. Use the no form of this command to reset all of the trunking characteristics
to the defaults. Use the no form with keywords to reset those characteristics to the defaults.
Syntax Description
allowed vlan vlan-list
native vlan vlan-id
pruning vlan vlan-list
The vlan-list format is all | none | [add | remove | except] vlan-atom where:
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switchport trunk {{allowed vlan vlan-list} | {native vlan vlan-id} | {pruning vlan vlan-list}}
no switchport trunk {{allowed vlan vlan-list} | {native vlan vlan-id} | {pruning vlan vlan-list}}
Set the list of allowed VLANs that can receive and send traffic on this
interface in tagged format when in trunking mode. See the following vlan-list
format. The none keyword is not valid. The default is all.
Set the native VLAN for sending and receiving untagged traffic when the
interface is in 802.1Q trunking mode. Valid IDs are from 1 to 4094 when the
enhanced software image (EI) is installed and 1 to 1001 when the standard
software image (SI) is installed. Do not enter leading zeros.
Set the list of VLANs that are enabled for VTP pruning when in trunking
mode. The all keyword is not valid.
all specifies all VLANs from 1 to 4094 when the EI is installed and 1 to 1005 when the SI is
installed. Do not enter leading zeros. This keyword is not allowed on commands that do not permit
all VLANs in the list to be set at the same time.
none means an empty list. This keyword is not allowed on commands that require certain VLANs
to be set or at least one VLAN to be set.
add adds the defined list of VLANs to those currently set instead of replacing the list. Valid IDs are
from 2 to 1001; extended-range VLAN IDs are valid in some cases.
Note You can add extended-range VLANs to the allowed VLAN list, but not to the
pruning-eligible VLAN list.
Separate nonconsecutive VLAN IDs with a comma; do not enter a space after the comma. Use a
hyphen to designate a range of IDs; do not enter a space before or after the hyphen. Do not enter
leading zeros.
remove removes the defined list of VLANs from those currently set instead of replacing the list.
Valid IDs are from 2 to 1001; extended-range VLAN IDs are valid in some cases.
Note You cannot remove VLAN 1 or VLANs 1002 to 1005 from the list. You can remove
extended-range VLANs (VLAN IDs greater than 1005) from the allowed VLAN list, but you
cannot remove them from the pruning-eligible list.
Separate nonconsecutive VLAN IDs with a comma; do not enter a space after the comma. Use a
hyphen to designate a range of IDs; do not enter a space before or after the hyphen. Do not enter
leading zeros.
Chapter 2 Cisco IOS Commands
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