Switchport Nonegotiate - Cisco Catalyst 3550 Command Reference Manual

Chapter 2 Catalyst 3550 Switch Cisco IOS Commands

switchport nonegotiate

Use the switchport nonegotiate interface configuration command to specify that Dynamic Trunking
Protocol (DTP) negotiation packets are not sent on the Layer 2 interface. The switch does not engage in
DTP negotiation on this interface. Use the no form of this command to return to the default setting.
Syntax Description
This command has no arguments or keywords.
Defaults
The default is to use DTP negotiation to determine trunking status.
Command Modes Interface configuration
Command History Release
12.1(4)EA1
Usage Guidelines
The no form of the switchport nonegotiate command removes nonegotiate status.
This command is valid only when the interface switchport mode is access or trunk (configured by using
the switchport mode access or the switchport mode trunk interface configuration command). This
command returns an error if you attempt to execute it in dynamic (auto or desirable) mode.
Internetworking devices that do not support DTP might forward DTP frames improperly and cause
misconfigurations. To avoid this, you should turn off DTP by using the switchport no negotiate
command to configure the interfaces connected to devices that do not support DTP to not forward DTP
frames.
When you enter the switchport nonegotiate command, DTP negotiation packets are not sent on the
interface. The device does or does not trunk according to the mode parameter: access or trunk.
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Examples
This example shows how to cause a port interface to refrain from negotiating trunking mode and to act
as a trunk or access port (depending on the mode set):
Switch(config-if)# switchport nonegotiate
You can verify your setting by entering the show interfaces interface-id switchport privileged EXEC
command.
OL-8566-01
switchport nonegotiate
no switchport nonegotiate
Modification
This command was introduced.
If you do not intend to trunk across those links, use the switchport mode access interface
configuration command to disable trunking.
To enable trunking on a device that does not support DTP, use the switchport mode trunk and
switchport nonegotiate interface configuration commands to cause the interface to become a trunk
but to not generate DTP frames.
Catalyst 3550 Multilayer Switch Command Reference
switchport nonegotiate
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