The advantages of virtual tunnel interfaces (VTIs) over GRE VPN solutions are which three of the
following? (Choose three.)

A.
VTI can support QoS.

B.
VTI provides a routable interface.

C.
VTI supports nonencrypted tunnels.

D.
VTI is more scalable than a GRE-based VPN solution.

E.
IPsec VTIs need fewer established SAs to cover different types of traffic, both unicast and
multicast, thus enabling improved scaling.

F.
IPsec VTIs require a loopback interface for configuration.

Explanation:
Page 391, CCNP Security SECURE 642-637 Official Cert Guide
IPsec VTIs have many benefits: