Trunking on Cisco IOS Switch

[charleswongcni (Charles W)]

Hi Rene,
I am, using WS-C2960S-24PD-L switch.
I got % Unrecognized command error message when I was going to config a trunk at interface Gi1/0/14.

CW2960#config terminal
Enter configuration commands, one per line.  End with CNTL/Z.
CW2960(config)#interface gi1/0/14
CW2960(config-if)#switchport trunk encapsulation ?
% Unrecognized command
CW2960(config-if)#switchport trunk encapsulation ▒

I would appreciate very much if you would explain the reason why?
Thank you.

[pooter4e (George A)]

Depending on the IOS version you’ll need to add “Switchport mode trunk”. Looks like you’re looking for the command “Switchport Trunk Encapsulation Dot1q”. That command was mostly removed in newer IOS.

[charleswongcni (Charles W)]

Hi George A,
Thank you for your reply.

It looks to me that the switch WS-C2960S-24PD-L is glued to “dot1q” and therefore “trunk encapsulation” command is not supported.

CW2960(config-if)#do sh int gi1/0/14 capabilities
GigabitEthernet1/0/14
  Model:	WS-C2960S-24PD-L
  Type:	10/100/1000BaseTX
  Speed:	10,100,1000,auto
  Duplex:	half,full,auto
  Trunk encap. type:	802.1Q
  Trunk mode:	on,off,desirable,nonegotiate
  Channel:	yes
  Broadcast suppression:	percentage(0-100)
  Flowcontrol:	rx-(off,on,desired),tx-(none)
  Fast Start:	yes
  QoS scheduling:	rx-(not configurable on per port basis),
	tx-(4q3t) (3t: Two configurable values and one fixed.)
  CoS rewrite:	yes
  ToS rewrite:	yes
  UDLD:	yes
  Inline power:	yes
  SPAN:	source/destination
  PortSecure:	yes
  Dot1x:	yes

Best regards,
Charles