Not able to change auto to trunk mode on switch

Unanswered Question
glen.grant Wed, 05/24/2006 - 15:30

You have to specifically set the encapsulation type first "switchport encapsulation dot1q" then try youir command...

glen.grant Wed, 05/24/2006 - 16:32

You need to specifically set the encapsulation first , "switchport encapsulation dot1q" then issue your trunk command...

ankurbhasin Wed, 05/24/2006 - 22:00

Hi All,

The command which he need to enter first is

"switchport trunk encapsulation dot1q " and then he can confgigure the interface in trunk mode.

So try this command

switch(config)#interface fa0/1

switch(config-if)#switchport trunk encapsulation dot1q

switch(config-if)#switchport mode trunk

and you will be good to go.

HTH, if yes please rate the post.


ankurbhasin Fri, 05/26/2006 - 00:31

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.


FatimaBeyelhadj Wed, 10/02/2013 - 09:28

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

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

Serge Amos Wed, 10/09/2013 - 05:39

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

zul qarnain Fri, 06/13/2014 - 17:14

Hi Ankur,

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



randdavis Tue, 07/12/2016 - 16:22

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


This Discussion