Which of the following IPv6 tunneling mechanisms support IPv6 IGP routing protocols?
(Choose two.)

A.
Automatic 6to4

B.
Manually configured tunnel

C.
ISATAP

D.
GRE

Explanation:
The two point-to-point tunneling methods—manually configured tunnel
and GRE—support IPv6 IGPs. The two multipoint tunneling methods—automatic

6to4 and ISATAP—do not.