Ipv4 Versus Ipv6

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IPv4 vs. IPv6

Anne-Marie Ethier Andrei Iotici

"This report was prepared for Professor L. Orozco-Barbosa in partial fulfillment of the requirements for the

course ELG/CEG 4183³

March 12, 2002



Presentation PlanIntroduction

Major Advantages to IPv6

Addresses

Packet Headers

Autoconfiguration

Neighbor DiscoverySecurity

Difficult transition



IntroductionWhat is IP?

The Internet Protocol (IP) is the method or

protocol by which data is sent from one computer to another on the Internet.

History

In 1978, the Office of the Secretary of Defense

(OSD) mandated the use of IPv4 for all ³host-to-host´ data exchange enabling IPv4 to become the

mechanism for the military to create integrated

versus stovepiped communications.



IP Address ShortageProliferation of Internet devices:

405M mobile phones sold in 2000

1B+ by 2005

New emerging populations:

China, Korea, Japan, India, Russia

Solution = IPv6



Advantages to IPv6Larger address space

Reduce end-to-end delay

Higher level of security

Mobility

No fragmentationNetwork autoconfiguration



Address FormatsIPv4

32-bit

Ex: 192.156.136.22

IPv6

128 bits

Ex:

1080:0:0:0:8:800:200C:417A

Or in compressed format:

1080::8:800:200C:417A



IPv4 Classes

0 1 8 16 24 31

A

B

C

netid hostid

1 0 netid hostid

1 1 0 netid hostid



IPv6 Address TypesUnicast

Global aggregatable

Site local

Link local

IPv4 compatible

AnycastMulticast

No more broadcast!

Link-localSite-localGlobal



Unicast Addresses

An address for a single interface

Global:

3 13 32 16 64

001 TLA ID NLA ID SLA ID Interface ID

TLA : Top-level aggregation NLA : Next-level aggregation

SLA : Site-level aggregation

The interface ID is based on the MAC address.



Anycast An address for a set of interfaces that

typically belong to different nodes.

96 bit 32 bit

0.0.0.0.0.0.192.168.30.1= ::192.168.30.1

= :: 0AB:1E01 ---???

0 Ipv4 address



Multicast An address for a set of interfaces (in a

given scope) that typically belong to

different nodes.



IPv4 Packet Header The basic IPv4 packet header has 12

fields with a total size of 20 octets (160

bits).



IPv6 Packet Header The basic IPv6 packet header has

8 fields with a total size of 40 octets

(320 bits).



Neighbor Discovery

Replaces ARP, ICMP, etc.

Used for

Router discovery Parameter/Prefix discovery

Address resolution

Address auto-configuration

Can provide the means to renumber homesubnets by forwarding solicitations to other subnets.



AutoconfigurationUsed by Neighbour Discovery

IPv6 no longer needs:

ARP

RARP

DHCP

BOOTP

Stateless vs. Stateful



Security Authentication Header (AH) IPv6 datagrams not encrypted

Keyed MD5 hashing algorithm proposed for standardauthentication algorithm Eliminates IP spoofing

Eliminates Host Masquarading

Encapsulating Security Payload Header (ESP) Provides data integrity and confidentiality

DES CBC encryption algorithm as standard (2 Modes)

Tunnel Mode: Whole IP packet encrypted (including header)

Transport Mode: Only payload encrypted



Difficult TransitionSome have already begun

experimenting with IPv6 on the internet

Dual IP layer

IPv6-over-IPv4 tunneling

For timeline information of the transition

efforts, browsehttp://www.ietf.org/html.charters/ngtrans-charter.html



Questions

Q1- What is the main reason for the switch from IPv4 to IPv6?

A1- IP address shortage

Q2 - Name 2 IPv6 address types and describe the reasons why

they are used. A2 ± Unicast: An address for a single interface.

Anycast: An address for a set of interfaces that typically

belong to different nodes. Assigning a unicast address to more

than one interface makes a unicast address an anycast address

Multicast: An IPv6 multicast address is an identifier for aset of interfaces that typically belong to different nodes. A packet

sent to a multicast address is delivered to all interfaces identified

by the multicast address.



Questions(next)

Q3 - Identify 2 differences between the IPv4 and IPv6packet headers.

A3 ± IPv6 IPv4

- 320 bits -160 bits

- 8 fields - 12 fields

- Flow Label - Checksum

Q4 - Explain the concept of "tunneling´

A4 - IPv6-over-IPv4 tunneling offers the possibility toencapsulate IPv6 packets within IPv4 headers in

order to carry them over IPv4 routing infrastructures.



Questions(next)

Q5 - Name the two main aspects in Internet security

and explain how their uses in IPv6.

A5 - Authentication Header (AH): only providesauthentication of the data packet and not encryption.

This is useful as a standalone when confidentiality is

not essential and only authentication is important.

Encapsulating Security Payload Header (ESP):provides data encryption.

Ipv4 Versus Ipv6

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