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Chapter Outline 2 Introduction

3 Address Space Allocation4 Autoconfiguration

5 Renumbering, Address Types and Migration

1 Overview

IPv6 Addressing

Before we start…_____ IPng __________ IPv6 __________ CIDR __________ NAT __________ Autoconfiguration__________ Unicast __________ Multicast __________ Anycast __________ IPv4-Compatible __________ IANA __________ VLSM __________ ICANN __________ Dual-Stack __________ Tunneling __________ Translation __________ Node _____ _____ Packet _____

Please write down the following Key Terms on a blank piece of paper leaving a small underline before and after each word. Label your paper IPv6 Pre/Post Concept Check.

Pre Check of Knowledge1. Rate yourself as to your perceived

knowledge of these key words.

2. Assess how much you already know about these terms by placing a (+), a check (√), or a zero (0) in the space to the left of each word.

Plus (+) = Expert Check (√) = Heard of it Zero (0) = Have not heard of it.

We will do a Post Check at the end of this chapter.

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1- Overview

IPv6 Defined Internet Protocol version 6 Originally known as IPng, or IP Next

Generation Network Layer protocol for packet switched

networks Successor of IPv4 which supports about 4.3

billion addresses (232 addresses) IPv6 increased the number of addresses to

(2128 addresses)

Benefits IPv6 longer address length is needed for:

Routing Aggregation Autoconfiguration of Addresses

Easier allocation of address blocks Flexibility of ISPs to subdivide blocks for

customers Organizations can subdivide blocks for

internal networks Embedded Quality of Service (QoS) to

support services like VoIP & IP Video Improved scalability for multicast routing More efficient packet forwarding

Okay, so what happened to IPv5?

IPv5 was NOT a successor to IPv6 Known as Internet ST (Stream

Protocol) Experimental protocol….Not in public

use

What’s driving the need for IPv6??

Internet growth Mobile devices

PDAs Mobile phones Tablet PCs

Gaming Voice/Video Security

Monitoring Appliances

Medical Imaging

Animal Tags Media Services Traffic Control Planes Automobiles Hotspots

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2- INTRODUCTION

What is the IPv6 address?An IPv6 address is 128 bits or 16 bytes (8 octets) long as shown in this figure. The address length in IPv6 is four times the length address in IPv4.

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Zero compression

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Show the unabbreviated colon hex notation for the following IPv6 addresses:

a. An address with 64 0s followed by 64 1s.b. An address with 128 0s.c. An address with 128 1s.d. An address with 128 alternative 1s and 0s.

Solutiona. 0000:0000:0000:0000:FFFF:FFFF:FFFF:FFFFb. 0000:0000:0000:0000:0000:0000:0000:0000c. FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFFd. AAAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA

Example 1

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The following shows the zero contraction version of addresses in Example 1 (part c and d cannot be abbreviated)

a. :: FFFF:FFFF:FFFF:FFFFb. ::c. FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFF:FFFFd. AAAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA:AAAA

Example 2

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Show abbreviations for the following addresses:a. 0000:0000:FFFF:0000:0000:0000:0000:0000b. 1234:2346:0000:0000:0000:0000:0000:1111c. 0000:0001:0000:0000:0000:0000:1200:1000d. 0000:0000:0000:0000:0000:FFFF:24.123.12.6

Example 3

Solution:a. 0:0:FFFF::b. 1234:2346::1111c. 0:1::1200:1000d. ::FFFF:24.123.12.6

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Decompress the following addresses and show the complete unabbreviated IPv6 address:

a. 1111::2222b. ::c. 0:1::d. AAAA:A:AA::1234

Solutiona. 1111:0000:0000:0000:0000:0000:0000:2222b. 0000:0000:0000:0000:0000:0000:0000:0000c. 0000:0001:0000:0000:0000:0000:0000:0000d. AAAA:000A:00AA:0000:0000:0000:0000:1234

Example 4

IPv6 Number of Addresses To give some idea about the number of

IPv6 addresses, let us assume that the number of people on the planet earth is soon to be 234 (more than 16 billion). Each person can have 294 addresses to use.

If we assign 260 addresses to the users each year (almost one billion each second), it takes 268 years to deplete addresses.

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3- ADDRESS SPACE ALLOCATION

• Like the address space of IPv4, the address space of IPv6 is divided into several blocks of varying size and each block is allocated for special purpose.

• Most of the blocks are still unassigned and have been left aside for future use.

• To better understand the allocation and the location of each block in address space, we first divide the whole address space into eight equal ranges.

• This division shows where each actual block is located .

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Unspecified address

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Compare the unspecified address in IPv4 to the unspecified addresses in IPv6.

SolutionIn both architectures, an unspecified address is an all-zero address. In IPv4 this address is part of class A address; in IPv6 this address is part of the reserved block.

Example 5

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Loopback address

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Compare the loop addresses in IPv4 to the loopback address in IPv6.

SolutionThere are two differences in this case. In classful addressing, a whole block is allocated for loopback addresses; it is the 127.0.0.0/8 - 127.255.255.255 , in IPv6 only one address is allocated as the loopback address; it is the ::1/128. In addition, the loopback block in classful addressing is part of the class A block. In IPv6, it is only one single address in the reserved block.You can find more about IP Reserved, Loopback and Private Addresses by visiting this website:http://www.tcpipguide.com/free/t_IPReservedPrivateandLoopbackAddresses-3.htm

Example 6

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Compatible address

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The Three Levels of Hierarchy

Global Routing Prefix (48 bits) is like the network ID in IPv4

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Mapping for EUI (Extended Unique Identifier)-64

• One of IPv6's key benefits over IPv4 is its capability for automatic interface addressing.

• By implementing the IEEE's 64-bit Extended Unique Identifier (EUI-64) format, a host can automatically assign itself a unique 64-bit IPv6 interface identifier without the need for manual configuration or DHCP.

• This is accomplished on Ethernet interfaces by referencing the already unique 48-bit MAC address, and reformatting that value to match the EUI-64 specification.

This can be described as having two steps: The first step is to convert the 48-bit MAC address to a 64-bit value. To do this, we break the MAC address into its two 24-bit halves: the Organizationally Unique Identifier (OUI) and the NIC specific part. The 16-bit hex value FFFE is then inserted between these two halves to form a 64-bit address.

Why FFFE? this is a reserved value which equipment manufacturers cannot include in "real" EUI-64 address assignments. In other words, any EUI-64 address having FFFE immediately following its OUI portion can be recognized as having been generated from an EUI-48 (or MAC) address.

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Mapping for Ethernet MAC

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Find the interface identifier if the Ethernet physical address is (F5-A9-23-14-7A-D2)16 using the format we defined for Ethernet addresses.

SolutionWe only need to change the seventh bit of the first octet from 0 to 1, insert two octet FFFE and change the format to colon hex notation. The result is F7A9:23FF:FE14:7AD2 in colon hex.

Example 7

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An organization is assigned the block 2000:1456:2474/48. What is the CIDR notation for the blocks in the first and second subnets in this organization?

SolutionTheoretically, the first and second subnets should use the block with subnet identifier 000116 and 000216. This means that the blocks are

2000:1456:2474:0001/64 and

2000:1456:2474:0002/64.

Example 8

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An organization is assigned the block 2000:1456:2474/48. What is the IPv6 address of an interface in the third subnet if the IEEE physical address of the computer is (F5-A9-23-14-7A-D2)16.

SolutionThe interface identifier is F7A9:23FF:FE14:7AD2 (see Example 7). If we add this identifier to the global prefix and the subnet identifier, we get:

Example 9

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4- AUTOCONFIGURATION

• One of the interesting features of IPv6 addressing is the autoconfiguration of hosts.

• As we discussed in IPv4, the host and routers are originally configured manually by the network manager using static addresses, however, the Dynamic Host Configuration Protocol, DHCP, can also be used to allocate an IPv4 address to a host that joins the network.

• In IPv6, DHCP protocol can still be used to allocate an IPv6 address to a host, but a host can also configure itself.

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Assume a host with Ethernet address (F5-A9-23-11-9B-E2)16 has joined the network. What would be its global unicast address if the global unicast prefix of the organization is 3A21:1216:2165 and the subnet identifier is 1232 ?

SolutionThe host first creates its interface identifier as

F7A9:23FF:FE11:9BE2 using the Ethernet MAC address read from its NIC card. Assuming that this address is unique, the host sends a router solicitation message and receives the router advertisement message that announces the combination of global unicast prefix and the subnet identifier as 3A21:1216:2165:1232. The host then appends its interface identifier to this prefix to find and store its global unicast address as:

Example 10

3A21:1216:2165:1232:F7A9:23FF:FE11:9BE2

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5- RENUMBERING , ADDRESS TYPES and MIGRATION• To allow sites to change the service provider, renumbering of

the address prefix (n) was built into IPv6 addressing. • As we discussed before, each site is given a prefix by the

service provider to which it is connected. If the site changes the provider, the address prefix needs to be changed.

• A router to which the site is connected to can advertise a new prefix and let the site use the old prefix for a short time before disabling it. In other words, during the transition period, a site has two prefixes.

IPv6 Provider-Based Addresses

The first IPv6 addresses will be allocated to a provider-based plan

Type: Set to “010” for provider-based addresses Registry: identifies the agency that registered the address

The following fields have a variable length (recommended lengths are in“()” ) Provider: Id of Internet access provider (16 bits)

Subscriber: Id of the organization at provider (24 bits)

Subnetwork: Id of subnet within organization (32 bits)

Interface: identifies an interface at a node (48 bits)

Registry ID

Provider ID010 Subscriber

IDInterface

IDSubnetwork

ID

IPv6 Address Types Unicast – identifies a single interface on a

single node. A unicast packet is delivered to the identified single interface.

Multicast - identifies a set of interfaces that belong to different nodes. A multicast packet is delivered to all identified interfaces.

Anycast – a global unicast address such as DNS that is assigned to a set of interfaces that belong to different nodes. An anycast packet is delivered to the closest interface.

For more information on Unicast, Multicast and Anycast, you may visit the website:http://www.omnisecu.com/tcpip/ipv6/unicast-multicast-anycast-types-of-network-communication-in-ipv6.php Broadcast – Not in IPv6!!!

IPv6 Unicast Addresses 64 bits for Global Routing and Subnet + 64

bits for Interface ID Prefix + Subnet ID + Interface ID = 128 bit IPv6

Address Prefix is the Global Routing Prefix (48 bits) Subnet ID is the subnet identifier within a site (16

bits) Interface ID is the interface identifier for a particular

host or other device (64 bits)From ONE: To ONE:SOURCE -----------------------------Unicast Destination

IPv6 Multicast Addresses 1st 8 bits are all 1’s i.e., 1111 1111; Translate into Hex: FF Indicator (8 bits) + Flags (4 bits) + Scope ID (4 bits) +

Group ID (112 bits) = IPv6 128 bit Multicast Address Indicator – 1st eight bits set to 1’s signifying a

multicast packet. Flags – 1st three are 0’s. The last is either a “0” for a

permanent/well known multicast address or a “1” for a temporary multicast address.

Scopes – Globally across the Internet or Locally within the organization

Group – Defines a particular group within a scope.

From ONE: To MANY:SOURCE Multicast Destinations

Multicast DestinationsMulticast Destinations

Multicast Scopes Node-Local

(within a node)Scope (1)

Link-Local (within a local network) Scope (2)

Site-Local (within a local site) Scope (5)

Organization-Local (within an organization) Scope (8)

Global (across the Internet) Scope (14)

Note: As the Scope ID Value Increases, the Scope expands to cover larger areas.

Well Known Multicast Addresses

FF01:0:0:0:0:0:1 used to multicast to all nodes for node-local. (Notice: FF signifies multicast, scope id of 1 signifies node-local, and group id of 1 signifies all nodes)

FF02:0:0:0:0:0:1 used to multicast to all nodes for link-local. (Notice: FF signifies multicast, scope id of 2 signifies link-local, and group id of 1 signifies all nodes)

FF01:0:0:0:0:0:2 used to multicast to all routers for node-local. (Notice: FF signifies multicast, scope id of 1 signifies node-local, and group id of 2 signifies all routers)

FF02:0:0:0:0:0:2 used to multicast to all routers for link-local. (Notice: FF signifies multicast, scope id of 2 signifies link-local, and group id of 2 signifies all routers)

FF05:0:0:0:0:0:2 used to multicast to all routers for node-local. (Notice: FF signifies multicast, scope id of 5 signifies site-local, and group id of 2 signifies all routers)

Multicasting to “all nodes” replaces IPv4 Broadcasts.

IPv6 Anycast Addresses Anycast Packets are new to IPv6 Automatically sends packet to the closest member within a

group. Provides flexibility when requesting a service provided by

several different routers. Designed for devices within the same network. Addresses assigned from Unicast Addressing space.From ONE: To ONE of Many:SOURCE ------------------------------- Multicast Destination

------------------------------- Multicast Destination----------------------------- CLOSEST Multicast Destination

IPv6 Special Addresses Reserved – reserved by IETF for special uses.

First eight bits are 00000000. Private – private addresses are local to a

particular site or company network and are never routed outside that network. First nine bits are: 111111101

Loopback – used for testing the “loop back” of the device. 0:0:0:0:0:0:0:1/128 or ::1/128

Unspecified – used in certain cases such as default routes but this address should not be assigned to any host. All 128 bits are zeroes noted as 0:0:0:0:0:0:0:0, or ::, or 0::0.

Who’s in charge? IANA – Internet Assigned Numbers Authority is in

charge of all IP address assignment and internet parameters. (owned and ran by ICANN)

ICANN – Internet Corporation for Assigned Names and Numbers is a private, non-profit company responsible for all registration tasks such as IP address assignment, domain name assignment, and protocol parameters management. (ICANN has allowed accredited registrars to register names in many of the top-level domains)

Often referred to as: IANA/ICANN or ICANN/IANA

Migrating from IPv4 to IPv6

Methods that make the migration easier: Dual-Stack – running both IPv4 and IPv6

simultaneously. Applications talk to both. Tunneling – wrapping or packaging one type

of packet into another to be sent on dissimilar network i.e., tunneling ipV6 packets on IPv4 network.

Translation – converting IPv4 to IPv6 and vice versa which can be complex and result in problems. Required for devices that only support one version. (temporary solution until more devices make the move to IPv6)

IPv6/IPv4 Address Embedding – embeds the IPv4 addresses within the IPv6 address structure

Dual-Stack Devices speak both

IPv6 and IPv4. Both IPv4 and IPv6 are

operational on all components(hosts, servers, routers, switches, and firewalls) attached to the network.

Dual Stack is the primary approach for introducing IPv6 into an IPv4 network

Tunneling Enables interconnection

of IP networks. IPv6 networks can be

connected through an IPv4 WAN link.

IPv6 packets are encapsulated and de-capsulated by border routers for transmission over the IPv4 WAN link.

Thus, IPv6 packets are tunneled through the IPv4 network cloud.

Translation Required when IPv6 host

needs to communicate with IPv4 host.

Application Level Gateways (ALGs) are required to translate.

Can be implemented in border routers and hosts.

Temporary Solution Complexity and

overhead issues

IPv6/IPv4 Address Embedding

These are special addresses assigned to IPv6-capable devices, such as so-called “dual stack” devices that speak both IPv4 and IPv6.

The first 80 bits are zeroes. They have also all zeroes for the

middle 16 bits; thus, they start off with a string of 96 zeroes, followed by the IPv4 address

IPv4 addresses are put in special format IPv6 address so they are recognized as IPv4 addresses by IPv6 devices.

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IPv4 Addressing Concepts and Their IPv6 Equivalents IPv4 Address IPv6 AddressAddress Length – 32 bits 128 bits

Address Representation - decimal hexadecimal

Internet address classes Not applicable in IPv6

Multicast addresses (224.0.0.0/4) IPv6 multicast addresses (FF00::/8)

Broadcast addresses Not applicable in IPv6

Unspecified address is 0.0.0.0 Unspecified address is ::

Loopback address is 127.0.0.1 Loopback address is ::1

Public IP addresses Global unicast addresses

Private IP addresses (10.0.0.0/8, 172.16.0.0/12, and 192.168.0.0/16)

Site-local addresses (FEC0::/10)

Autoconfigured addresses (169.254.0.0/16) Link-local addresses (FE80::/64)

Need private addressing and Network Address Translation (NAT)

Does not need NAT

Network bits representation: Subnet mask in dotted decimal notation or prefix length.

Network bits representation: Prefix length notation only.

IPv6 Post Check Now, go back to your IPv6 Pre/Post

Concept Check paper with your Key Terms

Rate your understanding of the Key Terms on the Right Side. Remember: (+) = Expert (√ ) = Heard of it (-) = Have not heard of it

Reflection as a group.

Summary IPv6 or Internet Protocol Version 6 is the successor to

IPv4 or Internet Protocol Version 4. It is needed to address the need for additional address space with an ever growing Internet population as well as new internet devices.

IPv6 addresses are written in Colon Hex notation. IPv6 addresses are Unicast, Multicast, and Anycast.

Broadcast is not part of IPv6. IPv6 has four special addresses: Reserved, Private,

Loopback, and Unspecified. Two colons in an address represent successive leading

zeroes. Full IPv6 deployment will take years. IPv4 and IPv6

must coexist in the meantime. Dual-Stack, Tunneling, Translation, and IPv6/IPv4 Address Embedding all make the migration easier.