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IPv6 Questions

May 3rd, 2017 Go to comments

Note: If you are not sure about IPv6, please read our IPv6 tutorial.

Question 1

Explanation

In this case we use two rules:

+ Leading zeros in a field are optional
+ Successive fields of 0 are represented as ::, but only once in an address

If you are not sure about IPV6, please read our IPv6 tutorial.

Question 2

Explanation

For more information about IPv6, please read our IPv6 tutorial.

Question 3

Explanation

Link-local addresses only used for communications within the local subnetwork (automatic address configuration, neighbor discovery, router discovery, and by many routing protocols). It is only valid on the current subnet. It is usually created dynamically using a link-local prefix of FE80::/10 and a 64-bit interface identifier (based on 48-bit MAC address).

Question 4

Question 5

Explanation

There are several ways to assign IPv6 to a device:

+ Static IPv6: The IPv6 address, subnet prefix length and default gateway are configured manually in the system configuration file.
+ Dynamic Host Configuration Protocol for IPv6 (DHCPv6): this mode requires a DHCPv6 server in your LAN. This is the most used mode for IPv6 assignment. There are two methods of DHCPv6:
stateless mode: Only extended information, such as primary and optional secondary DNS server, is obtained from a DHCPv6 server. IPv6 address is not assigned, so the IPv6 address from the Ethernet configuration is set for a Static address of Ethernet interface.
stateful mode: DHCPv6 server maintains a database of leased IPv6 addresses, and assigns to the client an unused IPv6 address. The DHCPv6 server specifies also a primary and optional secondary DNS server. The DNS server is used to resolve the IP address for a known host name.
+ IPv6 Stateless Address Autoconfiguration (SLAAC): provides the ability to address a host based on a network prefix that is advertised from a local network router via Router Advertisements (RA). Notice that with this mode, the device which requires an IPV6 always receive a dynamic IPv6 address.

The question asks about “stateless assignment of IPv6 addresses” which means stateless mode of DHCPv6.

Question 6

Explanation

This field is same as Time To Live (TTL) in IPv4, which is used to stop packet to loop in the network infinitely. The value of Hop Limit field is decremented by 1 when it passes a Layer 3 device (like a router). When this field reaches 0 the packet is dropped.

Question 7

Explanation

The “tunnel mode ipv6ip” command specifies IPv6 as the passenger protocol and IPv4 as both the encapsulation and transport protocol for the manual IPv6 tunnel. Notice that the tunnel source and destination are configured with IPv4 addressing and the tunnel interface is
configured with IPv6.

IPv6_tunneling.jpg

An example of configuring using this command is shown below:

R1(config)#int tunnel 1
R1(config-if)#ipv6 address 1cde:7ea:348:1::3/127
R1(config-if)#tunnel source 10.1.1.1
R1(config-if)#tunnel destination 10.1.1.2
R1(config-if)#tunnel mode ipv6ip

Question 8

Explanation

The IPv4 and IPv6 headers are shown below for your comparison:

IPv4_Headers.jpgIPv4 Header fields

IPv6_header.jpgIPv6 Header fields

IPv6 eliminates the Header Checksum field, which handles error checking in IPv4. IPv6 depends on reliable transmission in the data link protocols and on error checking in upper-layer protocols instead -> Answer C is correct.

While IPv4 header’s total length comprises a minimum of 20 octets (8 bits per octet), IPv6 header has only 8 fields with a fixed length of 40 octets -> Answer A is correct.

IPv4 header does not have a fixed length because of the Options fields. This field is used to convey additional information on the packet or on the way it should be processed. Routers, unless instructed otherwise, must process the Options in the IPv4 header. The processing of most header options pushes the packet into the slow path leading to a forwarding performance hit.

IPv4 Options perform a very important role in the IP protocol operation therefore the capability had to be preserved in IPv6. However, the impact of IPv4 Options on performance was taken into consideration in the development of IPv6. The functionality of Options is removed from the main header and implemented through a set of additional headers called extension headers. The “Next Header” field in IPv6 can be used to point to the extension headers.

IPv6_Next-header.jpg

Reference: http://www.cisco.com/en/US/technologies/tk648/tk872/technologies_white_paper0900aecd8054d37d.html

Question 9

Explanation

Link-local addresses only used for communications within the local subnetwork (automatic address configuration, neighbor discovery, router discovery, and by many routing protocols). It is only valid on the current subnet and are used to form routing adjacencies. Routers do not forward any packets with Link-Local source or destination addresses to other links. It is usually created dynamically using a link-local prefix of FE80::/10 (this includes addresses beginning with FE80:: through FEBF::) and a 64-bit interface identifier (based on 48-bit MAC address). For example, to configure a link-local address you can use this command:

R1(config-if)# ipv6 address fe80::1 link-local

Then your router interface may be assigned a link-local address (for example: FE80::20C:30FF:FE23:92E1).

Question 10

Explanation

Answer “DHCP” is not correct because DHCP can only assign IPv4 address. To assign IPv6 address, DHCPv6 should be used instead.

Answer “NHRP” is not correct because it is a protocol used in DMVPN.

Answer “ISATAP tunneling” is not correct because it is an IPv6 transition mechanism to transmit IPv6 packets between dual-stack nodes on top of an IPv4 network.

The two types of autoconfiguration are “stateless” and “stateful.”

Stateful autoconfiguration is the IPv6 equivalent of DHCP. A new protocol, called DHCPv6 (and based closely on DHCP), is used to pass out addressing and service information in the same way that DHCP is used in IPv4. This is called “stateful” because the DHCP server and the client must both maintain state information to keep addresses from conflicting, to handle leases, and to renew addresses over time -> Answer “IPv6 stateful autoconfiguration” is correct.

Stateless Autoconfiguration allows an interface to automatically “lease” an IPv6 address and does not require the establishment of an server to delve out address space. Stateless autoconfiguration allows a host to propose an address which will probably be unique (based on the network prefix and its Ethernet MAC address) and propose its use on the network. Because no server has to approve the use of the address, or pass it out, stateless autoconfiguration is simpler. This is the default mode of operation for most IPv6 systems, including servers. So answer “IPv6 stateless autoconfiguration” is correct too.

Question 11

Explanation

The correct syntax of the “boot” command is “boot system” path. In which the popular for path can be:
+ flash
+ rom
+ tftp
+ ftp
+ IP address (IP address of the server containing the system image file)

Therefore answers A, B, C are correct.

Comments (24) Comments
  1. Anonymous
    February 21st, 2017

    Choice for that question are:
    A. ping
    B. show ipv6
    Question 4

    Which command can you enter to verify that a 128-bit address is live and responding?
    A. traceroute
    B. telnet
    C. ping
    D. ping ipv6

  2. Anonymous
    February 21st, 2017

    Thank you to 9tut
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    I passed the CCNA exam february 20th and I scored 990

    one more time thank you to 9tut

  3. Anon
    February 28th, 2017

    Question 11 ??? in IPv6 area?

    Question 3 and 9 are the same !

    Fix it, please. Thx

  4. punisher
    February 28th, 2017

    questions 5 and 10 contradict each other.

  5. Apu Das
    March 7th, 2017

    Which command can you enter to verify that a 128-bit address is live and responding?

    A. traceroute
    B. telnet
    C. ping
    D. ping ipv6

    Please inform me correct answer.

  6. Aar@123
    March 8th, 2017

    Are these questions still valid?

  7. Anonymous
    March 8th, 2017

    There is no ‘ping ipv6’ as choice in the question, instead we have ‘show ipv6’
    The question will be:
    Which command can you enter to verify that a 128-bit address is live and responding?
    A. traceroute
    B. telnet
    C. ping
    D. show ipv6

  8. Aar@123
    March 10th, 2017

    Are the dumps available on 9tut valid??

  9. testsco
    March 16th, 2017

    hello
    maybe the want to say D.ping ipv6.

  10. Anonymous
    March 21st, 2017

    This was on my Test in March 2017

    Which statements about IPv6 prefixes are true?

    A. FEC0::/10 is used for IPv6 broadcast.
    B. FC00::/7 is used in private networks.
    C. FE80::/8 is used for link-local unicast.
    D. FE80::/10 is used for link-local unicast
    E. 2001::1/127 is used for loopback addresses.
    F. FF00::/8 is used for IPv6 multicast.

  11. Passed
    March 22nd, 2017

    Passed CCNA 200-125
    Studied Latest dumps 171+182+191

    https://docs.google.com/uc?export=download&id=0BwepsouMuqCjUnBBcFpWaVFFcEU

  12. Student
    March 28th, 2017

    the site above is a fake site i opened the link and payed $15 for the dump but they never sent me a link to download, when i try to contact them the number is unavailable. So be careful dont be tricked too.

    Fake site

    https://docs.google.com/uc?export=download&id=0BwepsouMuqCjUnBBcFpWaVFFcEU

  13. Anonymous
    April 26th, 2017

    please provide mcq as previously was…

  14. Muhammad Mohyuddin
    May 16th, 2017

    Which command can you enter to verify that a 128-bit address is live and responding?
    A. traceroute
    B. telnet
    C. ping
    D. ping ipv6

    Answer: D

  15. sk
    May 31st, 2017

    where are the questions releated to the above mentioned answers

  16. Anonymous
    June 14th, 2017

    i need 200-125 ccna dumps for preparing for exam pls send dumps questions
    {email not allowed}

  17. Yammato
    June 28th, 2017

    ATENTION!!!

    Hello. There is no “IPv6 ping” command in Cisco IOS, so the answer to question 4 is the “ping” command.

  18. Anonymous
    July 7th, 2017

    ping and ping ipv6 works fine

  19. idiott
    July 16th, 2017

    Anybody having VCE PLAYER crack if you having please send me link
    I preparing for CCNA exam for practicse purpose i need i searched lot of sites i didnt get..

  20. guli
    July 23rd, 2017

    Question 1 only answer D . A is incorrect answer because
    A. fd15:0db8:0000:0000:700:3:400F:527B last part :527B and in Question last part is :572B
    if am i right ?

  21. uspallata
    July 25th, 2017

    Q2. as far as I know: Unique-local is FD00::/8 and multicast is FF00::/16
    am I wrong?

  22. uspallata
    July 25th, 2017

    Sorry, I meant multicast FF02::/16

  23. McMacOff
    August 17th, 2017

    Question 5 correct answer is D! Stateless assignment uses autoconfiguration, DHCPv6 is used in stateful assigment. It’s even called in full as “IPv6 stateless autoconfiguration”. Proof here:
    https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipv6/configuration/15-2mt/ip6-15-2mt-book/ip6-statlss-auto.html

  24. 1Way
    September 23rd, 2017

    Question 5 is just poorly worded like a lot of the questions on here. DHCPv6 has a stateful and stateless mode, so it could be ‘B’.

    I opted for ‘D’ originally but I’m guessing it’s not ‘D’ because it says ‘autoconfiguration’ and not ‘IPv6 stateless autoconfiguration’.

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