IPv6 Questions and Answers for CCNA Exam 640-802

I have included IPv6 questions and answers from a number of sources including (A) the official Cisco CCNA exam guide book by Wendell Odom, (B) the website www.9tut.com,  (C) Chris Bryant,  (D) Anthony Sequeira and (E) the book "CCNA  Practice Questions" published by Pearson Certification . The Cisco book by Wendell Odom may possibly go more deeply into IPv6 than you  actually need for the CCNA exam so don't be discouraged!

(A) IPv6 Questions and Answers for CCNA Exam from book by Wendell Odom

The following 9 Questions and Answers are from the book "CCNA ICND2 - Official Exam Certification Guide" Cisco Press,  Second Edition (2008) by Wendell Odom

Question A- 1.       Which of the following is the most likely organization from which an enterprise could obtain an administrative assignment of a block of IPv6 global unicast IP addresses?
a.       An ISP
b.       ICANN
c.       An RIR                             
d.       Global unicast addresses are not administratively assigned by an outside organisation.

Answer:  A. One method for IPv6 global unicast address assignment is that ICANN (Internet Corporation for Assigned Network Numbers) allocates large address blocks to RIRs (Regional Internet Registry), RIRs assign smaller address blocks to ISPs (Internet Service Provider), and ISPs assign even smaller address blocks to their customers. 

Question A- 2.       Which of the following is the shortest valid abbreviation for FE80:0000:0000:0100:0000:0000:0000:0123?
a.       FE80::100::123
b.       FE8::1::123
c.       FE80::100:0:0:0:123:4567
d.       FE80:0:0:100::123 

Answer D. Inside a quartet, any leading 0s can be omitted, and one sequence of 1 or more quartets of all 0s can be replaced with double colons (::). The correct answer replaces the longer 3-quartet sequence of 0s with ::. 

Question A- 3 .       Which of the following answers lists a multicast IPv6 address?
a.       2000::1:1234:5678:9ABC
b.       FD80::1:1234:5678:9ABC
c.       FE80::1:1234:5678:9ABC
d.       FF80::1:1234:5678:9ABC

Answer D.
Global unicast addresses begin with 2000::/3, meaning that the first 3 bits match the value in hex 2000.
Similarly, unique local addresses match FD00::/8, and link local addresses match FE80::/10 (values that begin with FE8, FE9, FEA, and FED hex).
Multicast IPv6 addresses begin with FF00::/8, meaning that the first 2 hex digits are F. 

Question A- 4.       Which of the following answers list either a protocol or function that can be used by a host to dynamically learn its own IPv6 address?
a.       Stateful DHCP
b.       Stateless DHCP
c.       Stateless autoconfiguration
d.       Neighbor Discovery Protocol 

Answer: A and C. IPv6 supports stateful DHCP, which works similarly to IPv4’s DHCP protocol to dynamically assign the entire IP address. Stateless autoconfiguration also allows the assignment by finding the prefix from some nearby router and calculating the interface ID using the EUI-64 format. 

Question A- 5.       Which of the following help allow an IPv6 host to learn the IP address of a default gateway on its subnet?
a.       Stateful DHCP
b.       Stateless RS
c.       Stateless autoconfiguration
d.       Neighbor Discovery Protocol

Answer A and D. Stateless autoconfiguration only helps a host learn and form its own IP address, but it does not help the host learn a default gateway. Stateless RS is not a valid term or feature. Neighbor Discovery Protocol (NDP) is used for several purposes, including the same purpose as ARP in IPv4, and for learning configuration parameters like a default gateway IP address

Question A- 6.       Which of the following are routing protocols that support IPv6?
a.       RIPng
b.       RIP-2
c.       OSPFv2
d.       OSPFv3
e.       OSPFv4

Answer A and D.  OSPFv3, RIPng, EIGRP for IPv6, and MP-BGP4 all support IPv6. (Memory Hint: RIPng could also be regarded as RIP version 3!)

Question A- 7.       In the following configuration, this router’s Fa0/0 interface has a MAC address of 4444.4444.4444. Which of the following IPv6 addresses will the interface use?
ipv6 unicast-routing
ipv6 router rip tag1
interface FastEthernet0/0
ipv6 address 3456::1/64

a.       3456::C444:44FF:FE44:4444
b.       3456::4444:44FF:FE44:4444
c.       3456::1
d.       FE80::1
e.       FE80::6444:44FF:FE44:4444
f.        FE80::4444:4444:4444

Answer C and E. The configuration explicitly assigns the 3456::1 IP address. The interface also forms the EUI-64 interface ID 

(6444:44FF:FE44:4444), adding it to FE80::/64, to form the link local IP address. 

Question A- 8.       In the configuration text in the previous question, RIP was not working on interface Fa0/0. Which of the following configuration commands would enable RIP on Fa0/0?
a.       network 3456::/64
b.       network 3456::/16             
c.       network 3456::1/128
d.       ipv6 rip enable
e.       ipv6 rip tag1 enable

Answer E. RIPng configuration does not use a network command. Instead, the ipv6 rip command is configured on the interface, listing the same tag as on the ipv6 router rip command, and the enable keyword. 

Question A- 9.       Which of the following IPv4-to-IPv6 transition methods allows an IPv4-only host to communicate with an IPv6-only host?
a.       Dual-stack
b.       6to4 tunneling
c.       ISATAP tunneling
d.       NAT-PT

Answer D. Network Address Translation–Protocol Translation (NAT-PT) translates between IPv4 and IPv6, and vice versa. The two tunneling methods allow IPv6 hosts to communicate with other IPv6 hosts, sending the packets through an IPv4 network. Dual-stack allows a host or router to concurrently support both protocols.
[MY NOTE: NAT-PT is the only way an IPv4-only host can communicate with an IPv6-only host.  The other translation methods need  the two protocols to work together with each other.]

(B) IPv6 Questions in www.9tut.com website

The www.9tut.com website has a large number of CCNA exam questions (and Simulations, Simlets, Testlets etc) including  8 questions on IPv6. See
http://www.9tut.com/ccna-ipv6
The following are some of these questions:

Question B- 4. Which two of these statements are true of IPv6 address representation? (Choose two)

A – The first 64 bits represent the dynamically created interface ID.
B – A single interface may be assigned multiple IPV6 addresses of any type.
C – Every IPV6 interface contains at least one loopback address.
D – Leading zeros in an IPV6 16 bit hexadecimal field are mandatory.

Answer: B C   Leading zeros in IPv6 are optional so that 05C7 equals 5C7 and 0000 equals 0. Therefore D is not correct.

Question B- 5. Which three of the following are IPv6 transition mechanisms? (Choose three)

A – 6to4 tunneling
B – GRE tunneling
C – ISATAP tunneling
D – Teredo tunneling
E – VPN tunneling
F – PPP tunneling

Answer: A C D

Below is a summary of IPv6 transition technologies:

6 to 4 tunneling: This mechanism allows IPv6 sites to communicate with each other over the IPv4 network without explicit tunnel setup. The main advantage of this technology is that it requires no end-node reconfiguration and minimal router configuration but it is not intended as a permanent solution.

ISATAP tunneling (Intra-Site Automatic Tunnel Addressing Protocol): is a mechanism for transmitting IPv6 packets over IPv4 network. The word “automatic” means that once an ISATAP server/router has been set up, only the clients must be configured to connect to it.

Teredo tunneling: This mechanism tunnels IPv6 datagrams within IPv4 UDP datagrams, allowing private IPv4 address and IPv4 NAT traversal to be used.

In fact, GRE tunneling is also a IPv6 transition mechanism but is not mentioned in CCNA so we shouldn’t choose it (there are 4 types of IPv6 transition mechanisms mentioned in CCNA; they are: manual, 6-to-4, Teredo and ISATAP).

[MY NOTE: For the CCNA exam, be sure that you can recognize the NAMES of the 3 main tunneling types i.e. 6 to 4, ISATAP and Teredo ]

Question B- 6. Which two descriptions are correct about characteristics of IPv6 unicast addressing? (Choose two)

A – Global addresses start with 2000::/3.
B – Link-local addresses start with FF00::/10.
C – Link-local addresses start with FE00:/12.
D – There is only one loopback address and it is ::1.

Answer: A D

Below is the list of common kinds of IPv6 addresses:

Loopback address	::1
Link-local address	FE80::/10
Unique-local address	FD00::/8
Global address	2000::/3
Multicast address	FF00::/8

[My Note: The 9tut.com answer actually has the Site-local address  prefix FEC0::/10 in place of the Unique-local address prefix FD00::/8 above. However Site-local addresses are now obsolete and have been replaced by Unique-local. ]

Question B- 7. Select the valid IPv6 addresses. (Choose all apply)

A – ::192:168:0:1
B – 2002:c0a8:101::42
C – 2003:dead:beef:4dad:23:46:bb:101
D – ::
E – 2000::
F – 2001:3452:4952:2837::

Answer: A B C D F

Answers A and B  are correct because A is the short form of 0:0:0:0:192:168:0:1 and  B is the short form of 2002:c0a8:0101:0:0:0:0:0042.

Answer C is correct because it is the normal IPv6 address.

Answer D is correct because “::” is named the “unspecified” address and is typically used in the source field of a datagram that is sent by a device that seeks to have its IP address configured.

Answer E is not correct because a global-unicast IPv6 address is started with binary 001, denoted as 2000::/3 in IPv6 and it also known as an aggregatable global unicast address.The 2000:: (in particular, 2000::/3) is just a prefix and is not a valid IPv6 address.

The entire global-unicast IPv6 address range is from 2000::/128 to 3FFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF/128, resulting in a total usable space of over 42,535,295,865,117,307,932,921,825,928,971,000,000 addresses, which is only 1/8th of the entire IPv6 address space!

(C) IPv6 Questions by Chris Bryant

Chris Bryant has six practice IPv6 questions on his website at
http://www.thebryantadvantage.com/CCNACertificationPracticeExamIPVersion6.htm

His question 3  is related to the last question above
Question C- 3: What address type is indicated by the first 96 bits being set to zero?
Answer:  That's an IPv4-compatible address.

MY NOTE: Question 7 of the 9tut.com questions asks you to select valid IP v6 addresses and lists  ::192:168:0:1 as one of them. Note the double colon :: at the beginning. This represents 96 bits set to zero leaving 32 bits for the IPv4 address which is incorporated into the IPv6 address. 

Question C- 6. Where will you find IPv6 addresses beginning with 2002 and carrying a /48 prefix?

A. 6to4 tunnel edge routers

B. loopback interfaces

C. 6to4 tunnel access routers

D. Any link-layer master router

E. Any site-local DR

Answer A: 6to4 tunnel edge routers - the IPv6 routers that are communicating with each other through the IPv4 cloud - carry an IPv6 address beginning with 2002, followed by their IPv4 address expressed in hex. They carry a /48 prefix.

(D) IPv6 Questions by Anthony Sequeira

www.stormwindlive.com 
Question D- 1. Name three benefits of IPv6. Choose 3. 
a. Decreased reliance on multicast
b. Elimination of broadcast behavior
c. Enhanced DHCP usage
d. Increased security features
e. IP address autoconfiguration
Answer: b, d, e

Question D- 2. Which two statements regarding a link-local address are true? Choose 2. 
a. A link-local address is manually configured when needed
b. A link-local address begins FE80 
c. A link-local address is assigned by the ISATAP tunnel process 
d. A link-local address is based upon an existing Layer 2 address
 Answer:  b, d

Question D- 3. What is the loopback address used in IPv6? Choose 2. 
a. 0:0:0:0:0:0:0:1
b. 1:1:1:1:1:1:1:1
c. 1::
d. ::1
Answer: a, d

Question D- 4. Which of the following is NOTa feature of Anycast addressing in IPv6?
a. Same IPv6 address assigned to multiple nodes
b. Routing protocol makes the “nearest” determination
c. Supports many future potential applications 
d. Provides an any-to-many communication model
Answer: d

(E) from book "CCNA Practice Questions" - Chapter 8

http://my.safaribooksonline.com/book/certification/ccna/9780768682427

(The book "CCNA Practice Questions" by Jeremy CCIE No. 11727 Cioara is published by Pearson Certification. Selections from it are available free - including the IPv6 questions and answers.)
Question E- 4. Which of the following are invalid IPv6 communication types? (Choose two.)
 A .Unicast 
B. Multicast 
C. Broadcast 
D. Anycast 
E. Cryptocast

Answer: C, E.  IPv6 uses three types of communication: Unicast (one-to-one), Multicast (one-to-many), and Anycast (one-to-closest). Answer C is incorrect because the concept of Broadcast messaging is tied with the IPv4 protocol and is no longer valid in IPv6. Answer E is incorrect because there is no such thing as Cryptocast messaging.

Question E- 5. Which of the following are valid IPv6 addresses? (Choose three.)
A. 2001:0db8:0000:0000:0000:0000:1428:57ab
B. 2001:0db8::1428:57ab
C. 2001::1685:2123::1428:57ab
D. 2001:99:ab:1:99:2:1:9
E. 2001:1428:57ab:1685:2123:1428:57ab
Answer: A, B, D. An IPv6 address consists of eight sets that can be four hexadecimal characters each. Consecutive sets of zeros can be abbreviated with a double colon (::), but this can only be used once in each IP address. Leading zeros can also be dropped. Based on these rules, addresses from the question can be described as:

2001:0db8:0000:0000:0000:0000:1428:57ab (Valid, eight sets)
2001:0db8::1428:57ab (Valid, same address as above with abbreviation)
2001::1685:2123::1428:57ab (Invalid use of double colon)
2001:99:ab:1:99:2:1:9 (Valid, dropped leading zeros)
2001:1428:57ab:1685:2123: 1428:57ab (Invalid, only seven sets)

Question E- 18. In IPv6, Internet-valid addresses are known by what name? 
A. Private 
B. Public 
C. Unique 
D. Unspecified 
E. Global

Answer: E. The Internet-valid addresses are considered “global” addresses in IPv6. They are specified to begin with 2000::/3. Answer A is incorrect because private addresses are for use in a private network, as it currently happens in IPv4 addressing. Answer B is incorrect because global addresses have replaced public addresses. Answers C and D do not apply directly to IPv6 addressing.

Question E- 19. In IPv6, a ___________ address is used to communicate with hosts on the directly attached network and will never forward beyond the first router hop. 
A. Global 
B. Private 
C. Link local 
D. Private restricted 
E. Auto-generated
Answer: C. Link-local addressing is a new concept when moving from IPv4 to IPv6. Link-local addresses are used to communicate directly on a link. This is used for communication such as establishing OSPF neighbor relationships or sending RIP routes. Answer A is incorrect because global addresses can access the Internet directly. Answer B is incorrect because private IPv6 addresses can route through an organization. The addresses shown in answers D and E do not exist in the IPv6 environment.

Question E- 20. Which of the following commands could you use to assign an IPv6 address to your router? 

A .Router(config-if)#ip address fe01:3112:abcd::0001 255.255.255.0 
B .Router(config-if)#ip address fe01:3112:abcd::0001/48 
C .Router(config-if)#ip address 6 fe01:3112:abcd::0001 255.255.255.0 
D. Router(config-if)#ip address 6 fe01:3112:abcd::0001/48 
E. Router(config-if)#ipv6 address fe01:3112:abcd::0001 255.255.255.0 
F. Router(config-if)#ipv6 address fe01:3112:abcd::0001/48

Answer: F. IPv6 addresses are assigned using the ipv6 address command. In IPv6, there is no decimal version of the subnet mask; all subnet masks are written in bit-notation. Answers A, C, and E are incorrect because they use the decimal version of the subnet mask. Answers B and D are incorrect because they use the incorrect command.


Question E- 21 Which of the following commands could you use to start a RIPng process on your router? 

A. Router(config)#router RIPng 
B. Router(config)#ipv6 router rip RIPTagNo1 
C. Router(config)#routerv6 RIP 
D. Router(config)#ripv6

Answer B. The exact syntax to enable the RIPng (RIP for IPv6) routing protocol is ipv6 router rip <tag>. The tag can be anything from a number to a name; in this question, the tag was “RIPTagNo1”. This tag must be used when enabling RIP on an interface-by-interface basis. Answers A, C, and D will produce invalid syntax messages.

Question E-30. Which of the following commands enables the IPv6 protocol on a router? 
A. Router(config)#ipv6 unicast-routing 
B. Router(config)#ipv6 enable 
C. Router(config)#enable ipv6 
D. Router(config)#ipv6 
E. Router(config)#router ipv6

Answer: A. To enable the IPv6 protocol, use the command ipv6 unicast-routing from global configuration mode. All other answers produce an invalid syntax or incomplete command message.

(F) Miscellaneous

The following are two  questions from the Cisco CCNA Discovery course
Question F-1 Refer to the following command
RouterX (config-if) IPv6 address 2001:DB8:2222:7272::72/64
Which statement is true?

Answer: The complete IPv6 address is manually specified for the interface.
[My Note: This is a normal Global Unicast IPv6 address with a network prefix of 64 bits. In full it would be:
2001:0DB8:2222:7272:0000:0000:0000:0072/64 ]

Question F-2 What are two ways that some networks can use IPv6 addreses and still communicate over the Internet with their other networks that use IPv4 (choose two)?

The answers are:
Enable tunneling to allow IPv6 packets to be encapsulated and travel over IPv4 networks AND
Upgrade the IOS image on the IPv6 edge routers to an image that can translate IPv6 packets to IPv4 packets.