IPV6

Question 1

IPv6

Answer 1

▪ IPv4 essentially ran out of addresses due to proliferation of devices
▪ IPv6 addressing provides enough IP addresses for generations to come
▪ Enough IPv6 addresses for every person on the planet (5 x 1028)

Question 2

IPv6 Benefits

Answer 2

▪ No broadcasts
▪ No fragmentation
● Performs MTU (maximum transmission units) discovery for each
session
▪ Can coexist with IPv4 during transition
● Dual stack (run IPv4 and IPv6 simultaneously)
● IPv6 over IPv4 (tunneling over IPv4)
o Allows an existing IPv4 router to carry IPv6 traffic
o Encapsulates IPv6 packets within IPv4 headers to carry this
IPv6 data over IPv4 routers and other infrastructure
▪ Simplified header
● 5 fields instead of 12 fields

Question 3

IPv6 Address Structure

Answer 3

▪ Each hexadecimal digit is 4-bits
▪ 128-bits in an IPv6 address
▪ No more than 32 hexadecimal digits

Question 4

IPv6 Address Types: Unicast

Answer 4

• used to indentify single interface
  Globally routable unicast addresses
  ▪ Begins with 2000 to 3999
  o Link-local address
  ▪ Begins with FE80
  ▪ It uses stateless address autoconfiguration, or
  SLAAC

Question 5

IPv6 Address Types: Multicast

Answer 5

● Used to identify a group of interfaces so that a packet can be sent
to a multicast address and then be delivered to all of the
interfaces in the group
o Begins with FF

Question 6

IPv6 Address Types: Anycast

Answer 6

● Used to identify a set of interfaces so that a packet can be sent to
any member of a set

Question 7

Do you need DHCP for IPv6?

Answer 7

▪ IPv6 uses auto configuration to discover the current network and selects
its own host ID based on its MAC using the EUI64 process
▪ If you want to still use DHCP, there is a DHCPv6 protocol
▪ IPv6 uses Neighbor Discovery Protocol (NDP) to learn the Layer 2
addresses on the network

Question 8

Stateless Address Autoconfiguration (SLAAC)

Answer 8

Discovers the current network that an interface is located on and then
select its own host ID based on its MAC address using the EUI64 process
● Extended Unique Identifier (EUI)

Question 9

Neighbor Discovery Protocol (NDP)

Answer 9

Used to learn Layer 2 addresses on network
▪ Router Solicitation
● Hosts send message to locate routers on link
▪ Router Advertisement
● Router advertise their presence periodically and in response to
solicitation
▪ Neighbor Solicitation
● Used by nodes to determine link layer addresses
▪ Neighbor Advertisement
● Used by nodes to respond to solicitation messages
▪ Redirect

Question 10

Ipv6 Data Flows

Answer 10

▪ Three data flow methods, like IPv4
● Unicast
● Multicast
● Anycast (new to IPv6)

Question 11

IPv6 Unicast

Answer 11

Data travels from single spurce device to single destination device

Question 12

IPv6 Multicast

Answer 12

Data travels from single source device to multiple (but specific) destination devices

Question 13

IPv6 Anycast

Answer 13

▪ Designed to let one host initiate the efficient updating of router tables for
a group of hosts
▪ IPv6 can determine which gateway host is closest and sends the packets
to that host as though it were a unicast communication
▪ That host can anycast to another host in the group until all routing tables
are updated
▪ Data travels from a single source device to the device nearest to multiple
(but specific) destination devices