Switchport Trunk - Cisco Catalyst 2950 Command Reference Manual

Chapter 2 Catalyst 2950 and 2955 Cisco IOS Commands

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 the command without keywords 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:
•
•
•
•
•
0L-10102-01
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 IEEE 802.1Q trunking mode. The range is 1 to 4094.
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. 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
1 to 1005; extended-range VLAN IDs are valid in some cases.
You can add extended-range VLANs to the allowed VLAN list, but not to the
Note
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.
remove removes the defined list of VLANs from those currently set instead of replacing the list.
Valid IDs are 2 to 1001; extended-range VLAN IDs are valid in some cases. You cannot remove
VLAN 1 or VLANs 1002 to 1005 from the list.
Note 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.
except lists the VLANs that should be calculated by inverting the defined list of VLANs. (VLANs
are added except the ones specified.) Valid IDs are 1 to 1001. 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.
Catalyst 2950 and Catalyst 2955 Switch Command Reference
switchport trunk
2-509