Switchport Trunk - Cisco 4500M Command Reference Manual

switchport trunk

switchport trunk
To set trunk characteristics when an interface is in trunking mode, use the switchport trunk command.
To reset all of the trunking characteristics back to the original defaults, use the no form of this command.
Syntax Description
encapsulation isl
encapsulation dot1q
encapsulation negotiate
native vlan tag
native vlan vlan_id
allowed vlan vlan_list
pruning vlan vlan_list
Defaults
The default settings are as follows:
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Command Modes
Interface configuration
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switchport trunk encapsulation {isl | dot1q | negotiate}
no switchport trunk encapsulation
switchport trunk native vlan {tag | vlan_id}
no switchport trunk native vlan {tag | vlan_id}
switchport trunk allowed vlan vlan_list
no switchport trunk allowed vlan vlan_list
switchport trunk pruning vlan vlan_list
no switchport trunk pruning vlan vlan_list
Sets the trunk encapsulation format to ISL.
Sets the trunk encapsulation format to 802.1Q.
Specifies that if DISL and DTP negotiation do not resolve the
encapsulation format, ISL will be the selected format.
Specifies the tagging of native VLAN traffic on 802.1Q trunks.
Sets the native VLAN for the trunk in 802.1Q trunking mode.
Sets the list of allowed VLANs that transmit this interface in tagged
format when in trunking mode. See "Usage Guidelines" for formatting
guidelines for vlan_list.
Sets the list of VLANs that are enabled for VTP pruning when the switch
is in trunking mode. See "Usage Guidelines" for formatting guidelines
for vlan_list .
Encapsulation type is dependent on the platform or interface hardware.
Access VLANs and trunk interface native VLANs are a default VLAN corresponding to the platform
or interface hardware.
All VLAN lists include all VLANs.
Native VLAN tagging is enabled on the port if enabled globally.
Chapter2 Cisco IOS Commands for the Catalyst 4500 Series Switches
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