05-24-2006 02:55 PM - edited 03-03-2019 03:22 AM
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.
05-25-2006 10:13 AM
Thanks Ankur
Should we need to disable the concerned vlan of the port before entering the configuration.
05-26-2006 12:31 AM
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
10-02-2013 09:28 AM
This worked on one of the switches and not the other?!
What do you think could be the cause besides lab technical issues?
10-09-2013 05:39 AM
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
10-21-2013 07:01 AM
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...
06-13-2014 05:14 PM
Hi Ankur,
I have question why for switch multilayer is different from switch not multilayer if we need configure trunk on port?
Thanks,
05-23-2016 04:58 PM
Thank you that worked for me!
12-06-2016 01:20 AM
switchport trunk encapsulation dot1q is not working. After switchport trunk its not accepting encapsulation
05-23-2016 03:29 AM
Akser
07-12-2016 04:22 PM
Thanks your guidance worked great and now my ports are trunking.
08-11-2018 12:15 PM
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
03-13-2020 04:53 PM
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. -.-
11-05-2020 04:33 AM
(config-if)#switchport trunk encapsulation dot1q
04-03-2023 02:53 AM
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
04-08-2023 11:33 AM
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.
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