CCNA 1.8 and .9 - IPv6

Question 1

What is the IPv6 equivalent of ARP?

Answer 1

Neighbor Discovery Protocol (NDP)

Question 2

In IPv6, what is the difference between a global unicast and unique local address?

Answer 2

Global unicast are unique throughout the world, like a public IPv4 address is. Unique local is similar to using the private address ranges in IPv4 - they need to be NATted before accessing the global internet.

Question 3

IPv6 unique local addresses start with…

Answer 3

FD

Question 4

IPv6 multicast addresses begin with…

Answer 4

FF

Question 5

IPv6 link local addresses begin with…

Answer 5

FE80

Question 6

What IPv6 multicast address is used to send packets only to other IPv6 routers on the local link?

Answer 6

FF02::2

Question 7

What command enables IPv6 routing globally on the router?

Answer 7

ipv6 unicast-routing

Question 8

What are the EUI-64 steps for creating an address?

Answer 8

1) take the MAC address and split it in half
2) add “FFFE” in the middle
3) flip the seventh bit

Question 9

What is SLAAC?

Answer 9

Stateless Address Autoconfiguration

Question 10

What command enables SLAAC on an interface?

Answer 10

ipv6 address autoconfig

Question 11

What do IPv6 link-local addresses do and not do?

Answer 11

They do not carry user data. They are used for overhead protocols and routing. They are not advertised from one router to another subnet. e.g. NDP, next-hop addresses

Question 12

What is the prefix of an IPv6 link-local address?

Answer 12

FE80::/10

Question 13

True or false: when the global unicast ipv6 address is configured on an interface, the link-local address is also generated automatically.

Answer 13

True

Question 14

What are the four ways of configuring an IPv6 address on an interface?

Answer 14

1) ipv6 address <address/prefix-length>
2) ipv6 address <prefix/prefix-length> eui-64
3) ipv6 address autoconfig (SLAAC, uses eui-64)
4) ipv6 address dhcp (learns entire address without eui-64)

Question 15

What is the purpose of the “ipv6 enable” command?

Answer 15

It is used on point-to-point WAN links where a global unicast address simply isn’t necessary. It enables a link-local address for the purposes of routing packets, and that’s all.

Question 16

What is the reserved range for IPv6 multicast addresses?

Answer 16

FF30::/12

Question 17

List the uses for the following IPv6 multicast addresses:

1) FF02::1
2) FF02::2
3) FF02::5 and ::6
4) FF02::9
5) FF02::A
6) FF02::1:2

Answer 17

1) All IPv6 hosts on a link
2) All IPv6 router interfaces on a link
3) OSPFv3 routers (5) and DRs (6)
4) RIPng
5) EIGRPv6
6) DHCPv6 relay agent

Question 18

What are the five IPv6 multicast scopes?

Answer 18

1) FF01, interface-local, traffic from one process to another within the router
2) FF02, link-local, from one router to another, not forwarded beyond that
3) FF05, site-local, can be forwarded between routers but not over WAN links
4) FF08, organization-local, for an entire company
5) FF0E, no boundaries

Question 19

What is the “unspecified” IPv6 address?

Answer 19

:: (all 0s)

Question 20

What is the IPv6 loopback address?

Answer 20

::1 (127 binary 0s followed by a 1)

Question 21

How would you describe IPv6 “anycast”?

Answer 21

A host needs a service, it makes a request for that service, the router picks up the request and forwards it to the nearest router that provides that service.

Question 22

What prefix length is often used for an IPv6 anycast address?

Answer 22

/128 (host address)

Question 23

What are four functions of NDP?

Answer 23

1) Neighbor MAC discovery
2) Router discovery
3) SLAAC
4) Duplicate address detection (DAD)

Question 24

What are NS and NA messages?

Answer 24

NS = neighbor solicitation, asking for their MAC address
NA = neighbor advertisement, the reply with the MAC address

Question 25

What are the three steps in SLAAC?

Answer 25

1) Host sends RS to learn the local subnet prefix 2) Host builds an address using EUI-64 or a random address 3) Host uses DAD to verify the address's uniqueness

Question 26

True or false: An IPv6 host configured statically or via DHCP will still use DAD.

Answer 26

True

Question 27

If you want to use eui-64 calculation in your IPv6 address, you still need to give what info to the interface?

Answer 27

The prefix and length

Question 28

True or false: IPv6 static routes can use an outgoing interface as the next hop.

Answer 28

Partially true, partially false - you can use an interface on a serial interface, but not an ethernet interface.

Question 29

What are the three options for specifying the next hop when configuring an IPv6 static route?

Answer 29

1) GUA/ULA 2) outgoing interface + GUA/ULA 3) outgoing interface + LLA