The objective of this lab exercise is for you to learn and understand how to turn off the auto-negotiation of a trunk link.
Switch interfaces are set to automatically attempt to create a trunk link when connected to another switch. You need to know how to disable this behavior. Note that this behavior varies depending on the switch model.
This lab is suitable for the CCENT certification exam preparation.
This lab has a difficulty rating of 5/10.
When you are ready for your certification exam, you should complete this lab in no more than 15 minutes.
Please use the following topology to complete this lab exercise:
In preparation for the configuration, configure a hostname on Sw1 as well as Sw2.
Configure Sw1 so that auto-negotiation of trunking is disabled. Set the port to manually trunk.
Verify your configuration with the appropriate show commands.
Configuration and Verification
For reference information on configuring hostnames, please refer to earlier labs.
Sw1#show interface fast0/1 switchport Name: Fa0/1 Switchport: Enabled Administrative Mode: dynamic auto Operational Mode: down Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: native Negotiation of Trunking: On Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Sw1(config)#int fast0/1 Sw1(config-if)#switchport nonegotiate Command rejected: Conflict between ‘nonegotiate’ and ‘dynamic’ status. Sw1(config-if)#switchport mode trunk Sw1(config-if)#switchport nonegotiate Sw1(config-if)#end
NOTE: As you can see above, the interface cannot be left to dynamically become a trunk or access port if you want to disable auto-negotiation of trunking.
Sw1#show int fast0/1 switchport Name: Fa0/1 Switchport: Enabled Administrative Mode: trunk Operational Mode: down Administrative Trunking Encapsulation: dot1q Operational Trunking Encapsulation: dot1q Negotiation of Trunking: Off Access Mode VLAN: 1 (default) Trunking Native Mode VLAN: 1 (default) Voice VLAN: none