This chapter discusses IPv6, including its benefits over IPv4 such as a larger address space. It explains IPv6 addressing and configuration topics like global unicast addressing, stateful and stateless address autoconfiguration using DHCPv6, and IPv6 routing protocols. The chapter also covers IPv6 transition mechanisms from IPv4 like dual stack and tunneling approaches.

1. IPv6
Chapter 16

2. Chapter Objectives
 Explain the benefits and uses of IPv6
 Explain global unicast addressing, routing and subnetting
 Explain IPv6 Protocols and Addressing
 Configure IPv6 Routing and Routing Protocols
 Explain the IPv6 transition options
Chapter 1 2

3. Recall
 DH-1 has the key length of 768 bits. Similarly, DH2 and
DH5 have 1024 bits and 1536 bits respectively.
 Message integrity is a process in which a receiving VPN
device verifies that the data packet is not changed while
transmission.
 Authentication is a process in which a receiving VPN
device verifies that the received packet is sent by an
authorized VPN device.
 VPN can be configured by using the hostname, local
name or L2TP tunnel password.
Chapter 1 3

4. Benefits and uses of IPv6 - I
 Supports the features of the security protocol such as
IPSec to provide secure communication over the
Internet.
 Provides a way to change addresses that are assigned
to the hosts for maintaining address assignment within a
site.
Chapter 1 4

5. Benefits and uses of IPv6 - II
 Provides globally unicast addressing removes the need
for NAT/PAT
 IPv6 address assignment allows easier renumbering,
dynamic allocation and recovery of addresses.
 IPv6 routers do not recalculate a header checksum for
every packet, reducing overhead per packet.
Chapter 1 5

6. Global Route Aggregation for
Efficient Routing
 The strategies for IPv6 address assignment are as
follows:
 Public IPv6 addresses are grouped by major
geographical area.
 Address space is further sub-divided by ISP inside
each area.
 Address space inside each ISP in an area is further
sub-divided for each customer.
Chapter 1 6

7. Using DHCP for IPv6
 IPv6 hosts use the DHCP protocol, to get the IP
address, default router IP address, prefix length (mask)
and the DNS IP address.
 Using DHCP, the host sends the IPv6 packet for
searching DHCP server.
 The DHCPv4 server is used for IPv4 hosts. The
DHCPv4 holds information about the client, such as the
IP leased IP and the time period validity.
Chapter 1 7

8. Operational modes of DHCPv6 server
 The following are the two operational modes of DHCPv6
server:
 Stateful mode - In this mode the DHCPv6 server is
same as DHCPv4 server. It helps in tracking the
status of the client.
 Stateless mode - In this mode the server does not
track the status information.
Chapter 1 8

9. Stateless Auto configuration and
Router Advertisements - I
 The stateless auto configuration, allows the host to
calculate the IP address according to the prefix length
used on the subnet.
 It calculates the address using EUI-64 interface ID based
on its MAC address embedded into Network Interface
Card (NIC).
 The stateless auto configuration uses the NDP (Neighbor
Discovery Protocol) to discover the prefix length used on
LAN.
Chapter 1 9

10. Stateless Auto configuration and
Router Advertisements II
 It uses the following two NDP messages to discover the
IPv6 prefix used on LAN:
 Router Solicitation (RS) - The host sends an RS
multicast message to all the routers to identify the IPv6
prefix used on the subnet.
 Router Advertisement (RA) - The reply message of the
router is in the form of an RA message.
Chapter 1 10

11. Stateless Auto configuration and
Router Advertisements III
RS/RA Process
RS/RA PROCESS
Chapter 1 11

12. IPv6 Addresses
 Types of IPv6 addresses:
 Unicast - Assigns IP addresses to a single interface
that allows one host to send and receive data.
 Multicast - Represents IP addresses for a dynamic
group of hosts that send packets to all members of
that group.
 Anycast - They can be used by the server or routers
having same functionality for receiving the packets
from the client. The packets will be sent to the closest
in routing terms. This kind of addressing balances the
load between different servers.
Chapter 1 12

13. IPv6 Transition Options - I
 IPv6 resolves the issues of shortage of IP addresses
and larger routing table. A large number of devices
use IPv4, this the reason why few devices and their
software's do not support IPv6.
Chapter 1 13

14. IPv6 Transition Options - II
 The approaches are developed to migrate from IPv4 to
IPv6 are as follows:
 IPv6 Dual Stacks - IPv4 and IPv6 together can be used
by the host or router at the same time. This is known
as Dual stacks.
 Tunneling - Tunneling is used for migrating from IPv4
to IPv6. This function takes the IPv6 packet sent by
host, encapsulate it in IPv4 packet and forwards it over
the Internet. After the IPv4 header is removed the IPv6
packet is revealed.
Chapter 1 14

15. Summary - I
 IPv6 is an Internet protocol that supports much larger
addresses space than IPv4.
 Global unicast addresses are public and globally unique
IPv6 addresses that allow the hosts to communicate
over Internet.
 IPv6 is represented by 32 hexadecimal numbers
organized into 8 blocks, each block containing 4
hexadecimal (hex) digits separated by a colon.
Chapter 1 15

16. Summary - II
 You can abbreviate the IPv6 address using the following
rules:
 Neglecting the leading 0's in every block
 Putting (::) in place of continuous hex 0s
 IPv6 addressing supports classless addressing. It uses
prefixes to represent a range of consecutive IPv6
addresses.
 DHCP servers are used in two operational modes:
 Stateful
 Stateless
Chapter 1 16

17. Summary - III
 In stateful DHCPv6, IPv6 hosts use Dynamic Host
configuration (DHCP) protocol, to get the IP address,
default router IP address, prefix length (mass) and the
DNS IP address.
 IPv6 use the following routing protocols:
 RIPng
 OSPFv3
 MP-BGP4
 EIGRP for IPv6
Chapter 1 17

18. Summary - IV
 Two approaches are that can be used to migrate from
IPv4 to IPv6 are:
 IPv6 Dual Stacks
 Tunneling
 Some IPv6-to-IPv4 tunnels that can be used for
transition are given as follows:
 Manually Configured Tunnel (MCT)
 Dynamic 6to4 tunnels
 Intra-site automatic tunneling addressing protocol
(ISATAP)
 Teredo tunneling
Chapter 1 18