Which statement about the use of tunneling to migrate to IPv6 is true?

Which statement about the use of tunneling to migrate to IPv6 is true?
A . Tunneling is less secure than dual stack or translation.
B . Tunneling is more difficult to configure than dual stack or translation.
C . Tunneling does not enable users of the new protocol to communicate with users of the old protocol without dual-stack hosts.
D . Tunneling destinations are manually determined by the IPv4 address in the low-order 32 bits of IPv4­compatible IPv6 addresses.

View Answer

Answer: C

Explanation:

Using the tunneling option, organizations build an overlay network that tunnels one protocol over the other by encapsulating IPv6 packets within IPv4 packets and IPv4 packets within IPv6 packets. The advantage of this approach is that the new protocol can work without disturbing the old protocol, thus providing connectivity between users of the new protocol. Tunneling has two disadvantages, as discussed in RFC 6144: Users of the new architecture cannot use the services of the underlying infrastructure.

Tunneling does not enable users of the new protocol to communicate with users of the old protocol without dual-stack hosts, which negates interoperability.

Reference: http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/enterprise-ipv6-solution/ white_paper_c11-676278.html