CCNA - IPV6 Questions

Started by Vijayb, April 02, 2014, 12:37:46 AM

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Vijayb

#15
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!)

Vijayb

#16
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.

Vijayb

#17
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.

Vijayb

#18
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.]

Vijayb

#19
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.

Vijayb

#20
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 ]

Vijayb

#21
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. ]

Vijayb

#22
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!

Vijayb

#23
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.

Vijayb

#24
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.


Vijayb

#25
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

Vijayb

#26
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

Vijayb

#27
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

Vijayb

#28
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

Vijayb

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.