.0 subinterface

[psymonds7769]

Question:  On a cisco NCS-5500, running Version : 7.2.2.  If you configure a sub-interface under a TenGigE interface, and you specify that sub-interface to be a .0, i.e. te0/0/0/15.0, will this sub-interface by default be untagged?  Or do you still need to specify  encapsulation untagged command under the sub-interface for this to be untagged?  Thank you for any facts on this matter.

[balaji.bandi]

is the command accepted .0 sub-interface.

as i re-call this will give warning states (Configures 802.1Q encapsulation for the subinterface. The range is from 1 to 4000)

[psymonds7769]

Nope, no error message:

(config)#int te0/0/0/15.0
(config-subif)#

[balaji.bandi]

thats strange never come across that.

yes if that command accepts that may be bug, or may be you need to test. if you do not mentioned any dot1q then its untagged.

[Georg Pauwen]

Hello,

--> 

Nope, no error message:

(config)#int te0/0/0/15.0

What if you try and add an IP address to the subinterface ? That should, in theory, throw an error message...
(config-subif)#

[paul driver]

Hello

I would say NO it won’t be untagged as you should require to encapsulate the sub-interface prior to applying any ip address 

Only physical interfaces default to untagged native vlan 

[Richard Burts]

I agree with Paul that the digit you use for the interface number does not matter. The best practice is for the interface digit match the vlan number specified in the encapsulation dot1q command. But that is not required. What does matter is what vlan is specified in the encapsulation dot1q command and whether that vlan is either the default vlan or is specified as the native vlan.