A Service Provider provides a Layer 2 connection that is based on IEEE 802.1ad. When the customer tries to access a switch at the other side of the link by using SSH, the connection fails. What is the cause of this failure? 

Answer options:

A. The Service Provider omitted the command l2protocol-tunnel stp.
B. The Service Provider omitted the command l2protocol-tunnel vtp.
C. The Service Provider omitted the command vlan dot1q tag native.
D. The Service Provider omitted the command spanning-tree bpdufilter enable.

C

https://ccieblog.co.uk/qinq/802-1q-tunnelling-qinq