Not able to change auto to trunk mode on switch

[aksher]

SW-B-TOP(config-if)#switchport mode trunk

When trying to execute the above command am getting the following error.

Command rejected: An interface whose trunk encapsulation is "Auto" can not be configured to "trunk" mode.

[aksher]

Thanks Ankur

Should we need to disable the concerned vlan of the port before entering the configuration.

[ankurbhasin]

Hi Friend,

Thats not required because if you put the config which I posted in my previous mail it will take care of the issue.

HTH, if yes please rate the post.

Ankur

[FatimaBeyelhadj]

This worked on one of the switches and not the other?! 

What do you think could be the cause besides lab technical issues?

[serge123]

Could you run a " sh int gig #/# capabilities"

look under Trunk encap. type:

and Trunk mode:

it will give you capabilities information of the port

[jhotles]

The command is "switchport TRUNK encapsulation dot1q".  This will then allow the command "Switchport MODE TRUNK".

This is the core to the configuration - You NEED this command to run a standard trunk configuration otherwise it WILL NOT work...

[zul qarnain]

Hi Ankur,

I have question why for switch multilayer is different from switch not multilayer if we need configure trunk on port?

Thanks,

[Laura E Navarro]

Thank you that worked for me!

[suyash.ag92]

switchport trunk encapsulation dot1q is not working.  After switchport trunk its not accepting encapsulation

[Sudeb Das]

Akser

[randdavis]

Thanks your guidance worked great and now my ports are trunking.

[paul driver]

Hello

On some older switches and IOS -You need to specify its encapsulation first

int x/x/
switchport trunk encap dot 1q

switchport mode trunk

[PingPauly]

Failing of Cisco ...AGAIN

I cannot stress to how frustrating this course is when this command is NOT anywhere in the reading material for the course, not in the packet tracer activity, not in the labs. 

Yet here we are trying to get this cert. -.-

[negi.uk007]

(config-if)#switchport trunk encapsulation dot1q

[muhammadhammad7868]

SW-B-TOP(config-if)#switchport mode trunk

When trying to execute the above command am getting the following error.

Command rejected: An interface whose trunk encapsulation is "Auto" can not be configured to "trunk" mode.

----------------------------------------------------------------------------------------------------

switchport mode trunk ---  for this command, there's one prerequisite is that must have to configure the trunk encapsulation protocol manually, before there's auto set by default.

Manually configure the truk encapsulation protocol  ------ switchport trunk encapsulation dot1q or isl

then you can configure the switchport mode trunk command.

Thanks

[jimandrew33467]

It looks like you're trying to configure a trunk port on an interface with an "Auto" trunk encapsulation. You'll need to change the encapsulation to "dot1q" before configuring the Top Follow interface as a trunk. Try entering the command "SW-B-TOP(config-if)#switchport trunk encapsulation dot1q" first, and then try configuring the interface as a trunk again.