Answer to the IPv6 Addressing Question

IPv6 addressing is in the new ICND1 100-101 and CCNA 200-120 exams, and the previous post posed a related question. Today’s post wraps the topic, showing the answer. Check out the question before flipping the page!

• • • • • Link to the question
        • Link to the brief topic introduction

The Answer

(Wendell’s note to self: internal question number 112.)

Answer(s): B

The Explanation

You need to key facts to answer this question:

• OSPF Version 3 (OSPFv3) uses link local addresses as the next-hop address for the IPv6 routes it adds to the IPv6 routing table.
• Link local addresses begin with an initial four hex digits of FE80.

Armed with those two facts, you can scan the list looking for any link local addresses, find only one (in answer B), and answer the question.

Another Question!

I could go on to explain more about the incorrect answers, but instead, I think I’ll ask another, with the same exact answers. Same scenario even. The only difference is the part of the question highlighted in yellow below. Here’s the next one:

(Question 113:)

Host A, in a bank branch office in Atlanta, Ga., is able to send IPv6 packets back and forth with server S1 in Charlotte, NC. The routers use OSPFv3. Which of the following address(es) could be used as the source IPv6 address of the packet that flows from Host A to server S1?

A) 3456:1234:5678:9AB:1111:2222:3333:4444

B) FE80::200:FF:FE00:1111

C) FD00:DEAD:BEEF:CAFE:101:20:3:1111

D) FF02::1:FF00:1234

E) ::

F) FF02::5

(Note that unlike the real Cisco exams, this sample question does NOT identify the number of correct answers, just to add to the challenge level.)

More Practice Questions:

This question is like those you get if when you buy the ICND1 100-101 Official Cert Guide. This blog also lists various practice questions as well. For more questions on a large variety of topics:

• Look at the Questions tab in the www.ccentskills.com blog
• Look at the Questions tab in the www.ccnaskills.com blog
• Use the practice tests that come with the printed version of the book
• Get additional exam banks, even more than the print book, with the Premium Edition of the Book, available only from the publisher