Module 6: IPv6 Fundamentals

Module 6: IPv6 Fundamentals

• Introduction to IPv6

• Unicast IPv6 Addresses

• Configuring IPv6

Lesson 1: Introduction to IPv6

• IPv4 Limitations

• IPv6 Improvements

• Discussion: IPv6 Challenges

• IPv6 Address Space

• IPv6 Address Syntax

• IPv6 Address Types

• Neighbor Discovery

IPv4 Limitations

The limitations of IPv4 are:

• Limited number of addresses

• Routing difficult to manage

• Host configuration is complex

• No built-in security

• Limited quality of service

IPv6 Improvements

Improvements in IPv6 include:

• Larger address space

• More efficient routing

• Simpler host configuration

• Built-in security

• Better prioritized delivery support

• Redesigned headers for efficient processing and extensibility

Discussion: IPv6 Challenges

What are some of the challenges of implementing IPv6?

IPv6 Address Space

The IPv6 address space is:

• 128 bits

• Extremely large

• Allows routing flexibility

IPv6 Address Syntax

IPv6 addresses are:

• Displayed in hexadecimal

• Can use zero compression

• Use a prefix to define the network portion of the address rather than a subnet mask

Examples:

2001:0DB8:0000:0000:02AA:00FF:FE28:9C5A/64

2001:DB8:0:0:2AA:FF:FE28:9C5A/64

2001:DB8::2AA:FF:FE28:9C5A/64

IPv6 Address Types

Type Description

Unicast Equivalent to IPv4 unicast

Multicast Additional unicast address types

Anycast Equivalent to IPv4 multicast

IPv6 addresses types include:

Neighbor Discovery

Some of the ND functions are:

• Router discovery

• Prefix discovery

• Parameter discovery

• Address auto-configuration

• Address resolution

• Duplicate address detection

Neighbor Discovery is a set of messages and processes that determine relationships between neighboring nodes

Neighbor Discovery is a set of messages and processes that determine relationships between neighboring nodes

Lesson 2: Unicast IPv6 Addresses

• Interface Identifiers

• What Are Global Unicast Addresses?

• What Are Link-Local Addresses?

• What Are Unique Local Unicast Addresses?

• Special IPv6 Addresses

Interface Identifiers

An interface identifier is:

•The last 64 bits of an IPv6 address

•Used as a media access control (MAC) address is in IPv4

An interface identifier can be:

•An EUI-64 address

•A randomly generated temporary identifier

•A randomly generated permanent identifier

•A manually assigned identifier

What Are Global Unicast Addresses?

Subnet ID001 Global Routing Prefix Interface ID

48 bits 16 bits 64 bits

Public Topology Site Topology Interface Identifier

Global unicast addresses are:

• Equivalent to public IPv4 addresses

• Globally routable on the Internet

• Designed for hierarchical routing

Link-local addresses are:

• Equivalent to APIPA IPv4 addresses

• Unique on the local network

• Required for Neighbor Discovery

• Always automatically configured for an interface

• Begin with FE80::/64

What Are Link-Local Addresses?

Interface ID000 … 0001111 1110 10

10 bits 54 bits 64 bits

What Are Unique Local Unicast Addresses

Unique local unicast addresses:

• Are equivalent to IPv4 private IP addresses

• Have a 40 bit Global ID you should use for your entire organization

• Have 16 bits designated for subnetting

• Replace site local addresses

1111 110 Global IDL Subnet ID Interface ID

7 bits 40 bits 64 bits16 bits

Special IPv6 Addresses

Unspecified address:

• 0:0:0:0:0:0:0:0:0 or ::

• Equivalent to IPv4 address 0.0.0.0

• Only ever used as a source address

Loopback address:

• 0:0:0:0:0:0:0:0:1 or ::1

• Equivalent to IPv4 address 127.0.0.1

• Used for testing the local IPv6 stack

Lesson 3: Configuring IPv6

• IPv6 Addresses Assigned to a Host

• Demonstration: Configuring IPv6

• Address Autoconfiguration

• The Autoconfiguration Process

• What Is DHCPv6?

IPv6 Addresses Assigned to a Host

Unicast addresses:

• A link local address for each interface

• A unique local unicast address or global unicast address

• A loopback interface with ::1

Multicast addresses:

• The interface-local scope all-nodes multicast address (FF01::1)

• The link-local scope all-nodes multicast address (FF02::1)

• The solicited-node address for each unicast address on each interface

• The multicast addresses of joined groups on each interface

Demonstration: Configuring IPv6

In this demonstration, you will see how to configure IPv6 with a static address

Address Autoconfiguration

Address autoconfiguration can be:

• Stateful

• Stateless

Autoconfigured address states:

• Tentative

• Valid

• Preferred

• Deprecated

• Invalid

Valid

Preferred Deprecated InvalidTentative

Preferred Lifetime

Valid Lifetime

Time

The Autoconfiguration ProcessDerive link-local address:

FE80::[interface ID]

Send multicast neighbor solicitation with target address set to derived

local-link address

Neighbor advertisemen

t response received?

Initialize link-local address

Send router solicitation

Router advertisement response received?

Stop autoconfiguration

Use stateful address configuration protocol

Yes

No

No

Yes

Set hop limit, reachable time, retrans timer, MTU

Are prefix information

options present?

Is managed address

configuration flag set to 1?

Stop autoconfiguration

Process prefix options

Yes

No

Is other stateful

configuration flag set to 1?

What Is DHCPv6?

Client sends a Solicit message

Server sends an Advertise message

Client sends a Request message

Server sends a Reply message

11

22

33

44

Lab: Configuring IPv6

• Exercise 1: Defining IPv6 Networks for Internal Use

• Exercise 2: Configuring a Static IPv6 Address on a Server

Estimated time: 30 minutes

Logon information

Virtual machine NYC-DC1

User name Administrator

Password Pa$$w0rd

Lab Review

• Why was NYC-DC1 only configured with a link-local IPv6 address?

• How can you quickly identify that an IPv6 address is a unique local unicast address?

Module Review and Takeaways

• Review Questions

• Real-world Issues and Scenarios

• Best Practices