Implementing Cisco IP Routing (CCNP ROUTE, legacy) — Question 170

After you review the output of the command show ipv6 interface brief, you see that several IPv6 addresses have the 16-bit hexadecimal value of "FFFE" inserted into the address. Based on this information, what do you conclude about these IPv6 addresses?

Answer options

• A. IEEE EUI-64 was implemented when assigning IPv6 addresses on the device.
• B. The addresses were misconfigured and will not function as intended.
• C. IPv6 addresses containing "FFFE" indicate that the address is reserved for multicast.
• D. The IPv6 universal/local flag (bit 7) was flipped.

Correct answer:

Explanation

The correct answer is A because the presence of 'FFFE' in the IPv6 address indicates that the addresses were generated using the IEEE EUI-64 format, which is standard for deriving IPv6 addresses from MAC addresses. Option B is incorrect as the addresses are valid and not misconfigured. Option C is wrong since 'FFFE' does not indicate a multicast address; multicast addresses are separate and do not typically include this sequence. Option D is also incorrect because the universal/local flag is not directly related to the inclusion of 'FFFE'.