An engineer is reviewing another engineer’s sample configuration for a GRE tunnel used to
pass IPv6 traffiC. The tunnel has not yet been configured on the router. Which of the
following commands is not required for the configuration to pass IPv6 traffic?

A.
tunnel source

B.
tunnel destination

C.
tunnel mode

D.
All these commands are requireD.

Explanation:
IOS defaults to use GRE encapsulation mode on tunnel interfaces, so the tunnel
mode command is not requireD. The mode will default to GRE. The tunnel source
and tunnel destination commands are requireD.