Module 4

Configuring and Troubleshooting IPv6

TCP/IP

Module Overview

•Overview of IPv6

• IPv6 Addressing

•Coexistence with IPv6

• IPv6 Transition Technologies

• Transitioning from IPv4 to IPv6

• Troubleshooting IPv6

Lesson 1: Overview of IPv6

•Benefits of IPv6

•Differences Between IPv4 and IPv6

• IPv6 Address Space

• Practice: Converting from Binary to Hexadecimal

Benefits of IPv6

Benefits of IPv6 include:

• Large address space

• Hierarchical addressing and routing infrastructure

• Stateless and Stateful address configuration

• Required support for IPsec

• Restores end-to-end communication

• Prioritized delivery

• New protocol for neighboring node interaction

• Extensibility

Differences Between IPv4 and IPv6

IPv4 IPv6

Source and destination addresses

32 bits (4 bytes) in length 128 bits (16 bytes) in length

IPsec support Optional Required

Address Resolution Protocol

Broadcast ARP Request frames resolve IPv4 address to link layer address

ARP Request frames replaced with multicast Neighbor Solicitation messages

Internet Group Management Protocol

Manages local subnet group membership

IGMP replaced with MLD messages

ICMP Router Discovery

Determines IPv4 address of default gateway

Replaced with ICMPv6 Router Solicitation and Router Advertisement messages

Broadcast addresses Sends traffic to all nodes on a subnet

Uses a link-local scope, all-nodes multicast address instead of an IPv6 broadcast address

ConfigurationConfigured manually or through DHCP

Does not require manual configuration or DHCP

Resource recordsUses A resource records in DNS to map host names to IPv4 addresses

Uses AAAA resource records in DNS to map host names to IPv6 addresses

IPv6 Address Space

Address Syntax:

• 128-bit address in binary:

• 128-bit address divided into 16-bit boundaries:

• Each 16-bit block converted to HEX (base 16):

• Further simplify by removing leading zeros:

0010000000000001000011011011100000000000000000000010111100111011 0000001010101010000000001111111111111110001010001001110001011010

0010000000000001 0000110110111000 0000000000000000 0010111100111011 0000001010101010 0000000011111111 1111111000101000 1001110001011010

2001:0DB8:0000:2F3B:02AA:00FF:FE28:9C5A

2001:DB8:0:2F3B:2AA:FF:FE28:9C5A

Converting from Binary to Hexadecimal

[0010][1111][0011][1011]

8 4 2 1

[0 0 1 0] 0+0+2+0=2

[1 1 1 1] 8+4+2+1=F

[0 0 1 1] 0+0+2+1=3

[1 0 1 1] 8+0+2+1=B

= 2F3B

• 128-bit address in binary:

• 128-bit address divided into 16-bit boundaries:

• Each 16-bit block converted to HEX (base 16):

• Further simplify by removing leading zeros:

00100000000000010000110110111000000000000000000000101111001110110000001010101010000000001111111111111110001010001001110001011010

0010000000000001 0000110110111000 00000000000000000010111100111011 0000001010101010 0000000011111111 1111111000101000 1001110001011010

2001:0DB8:0000:2F3B:02AA:00FF:FE28:9C5A

2001:DB8:0:2F3B:2AA:FF:FE28:9C5A

Lesson 2: IPv6 Addressing

• IPv6 Prefixes

•Unicast IPv6 Address Types

•Zone IDs

•Address Autoconfiguration for IPv6

•Demonstration: How to Configure IPv6 Client Settings

IPv6 Prefixes

AllocationFormat prefix binary value

Format prefix hexadecimal value

Fraction of the address space

Reserved 0000 0000 - 1/256

Aggregatable global unicast addresses

001 2 or 3 1/8

Link-local unicast addresses

1111 1110 10 FE8 1/1024

Site-local unicast addresses

1111 1110 FD00 1/256

Multicast addresses 1111 1111 FF 1/256

Unicast IPv6 Address Types

• Global unicast addresses

• Local-use unicast addresses

• Unique local IPv6 unicast addresses

Zone IDs

Zone IDs

• fe80::2b0:d0ff:fee9:4143%3

• fec0::f282:2b0:d0ff:fee9:4143%2

Address Autoconfiguration for IPv6

Preferred Deprecated InvalidTentative

Valid

Time

Valid Lifetime

Preferred Lifetime

Autoconfigured IP Timeline

If managed flag set,use DHCPv66 Add prefixes5Check the router for prefixes4Check for a router on the network3Check for address conflicts using neighbor solicitation2 Derive Link-Local Address1

fe80::d593:e1e:e612:53e4%10

Router configuration information

Additional router prefixes

DHCPv6 information received

IPv6 Client

IPv6 DHCP Server configured with SiteLocal Scope

IPv6 Router

Demonstration: How to Configure IPv6 Client Settings

This demonstration shows how to:

•Configure a DHCP Scope for IPv6 Clients

•Configure the client computer

Lesson 3: Coexistence with IPv6

•What Are Node Types?

• IPv4 and IPv6 Coexistence

•What Is a Dual Layer Architecture?

•What Is a Dual Stack Architecture?

•How DNS Supports IPv6

•Demonstration: How to Configure DNS to Support IPv6

•What Is IPv6 Over IPv4 Tunneling?

What Are Node Types?

IPv4 Network

IPv6 Network

IPv4/IPv6 Node

IPv4 Only Node

IPv6 Only Node

IPv4 and IPv6 Coexistence

Methods for providing coexistence of IPv4 and IPv6:

• Dual IP layer architecture (Windows Vista, Windows Server 2008, Windows 7, and Windows Server 2008 R2)

• Dual stack architecture(Windows Server 2003 and Windows XP)

• DNS Infrastructure requirements

• IPv6 over IPv4 tunneling

What Is a Dual-Layer Architecture?

Dual layer can create:

• IPv4 packets

• IPv6 packets

• IPv6 over IPv4 packets

Transport Layer (TCP/UDP)

IPv6

Network Interface Layer

IPv4

Application Layer

IPv6 IPv4

IPv6 over IPv4

What Is a Dual-Stack Architecture?

Dual stack can create:

• IPv4 packets

• IPv6 packets

• IPv6 over IPv4 packets

TCP/UDP

IPv6

Network Interface Layer

IPv4

IPv6 IPv4

IPv6 over IPv4

TCP/UDP

Application Layer

How DNS Supports IPv6

DNS support for IPv6:

• DNS Host records are classified as AAAA records

• Pointer Records are configured in the IP6.ARPA zone

• DNS tries to return the appropriate address (either IP 4 or IP 6 depending on the Address Selection rules)

Demonstration: How to Configure DNS to Support IPv6

This demonstration shows how to:

•Configure the bindings for the DNS service

•Verify the presence of AAAA records in Contoso.com

What Is IPv6 Over IPv4 Tunneling?

IPv4 Packet

IPv6 Packet

IPv4

IPv6

IPv6 over IPv4 tunneling allows IPv6 to communicate through an IPv4 network

IPv4 header

Upper layer protocol data unit

Extension headers

IPv6 header

Upper layer protocol data unit

Extension headers

IPv6 header

IPv4 Packet

IPv6 Packet

Lesson 4: IPv6 Transition Technologies

• IPv6 Transition Technologies Use

•What Is ISATAP?

•What Is 6to4?

•What Is Teredo?

•What Is PortProxy?

IPv6 Transition Technologies Use

Tunneling Technology

Usage

ISATAP

• Local intranets

• Autoconfiguration on host

• Allows IPv6 nodes to communicate over an IPv4 subnet

• Enabled by default

6to4

• IPv6 to IPv6 networks over the IPv4 Internet

• Autoconfiguration on host

• Enabled by default

Teredo• IPv6 to IPv6 through IPv4 NAT

• Disabled by default

What Is ISATAP?

DNS query for “ISATAP”1

IPv6-capablenetwork

IPv4-onlyintranet

ISATAP Host

ISATAP Host

ISATAP Router

DNS Server

1 2

3

IPv4-encapsulated routersolicitation2

IPv4-encapsulated routeradvertisement3

IPv4 traffic

IPv6 tunneledwith IPv4

How ISATAP Tunneling Works

ISATAP Router

• Forwards packets between ISATAP hosts and hosts on other IPv6 subnets (optional)

• Advertises subnet prefixes assigned to the logical ISATAP subnet on which ISATAP hosts are located

• ISATAP hosts use the advertised subnet prefixes to configure global ISATAP addresses

• The other subnets can be subnets in an IPv6-capable portion of the organization's network or the IPv6 Internet

• ISATAP addresses:

• [64-bit unicast prefix]:0:5EFE:w.x.y.z

• w.x.y.z is a public or private IPv4 address

• Example: FE80::5EFE:157.59.137.133

• Address assignment and automatic tunneling technology for unicast IPv6 traffic between IPv6/IPv4 nodes across an IPv4 intranet

• ISATAP treats an IPv4 infrastructure as a single link

What Is 6to4?

IPv6 host BIPv6/IPv4

6to4 relayIPv6/IPv4

6to4 routerIPv6/IPv4

6to4 routerIPv6/IPv4

IPv6 host CIPv6/IPv4

IPv6 Internet

IPv6 host DIPv6-only

IPv6 host AIPv6/IPv4

Site 1

Site 2

IPv4 Internet

Field Value

IPv6 Source Address 2002:9D3C:5B7B:1::1

IPv6 Destination Address 2002:836B:D231:2::3

IPv4 Source Address 157.60.91.123

IPv4 Destination Address 131.107.210.49

• 6to4 address:

2002:WWXX:YYZZ:Subnet_ID:Interface_ID

• Address assignment and automatic tunneling technology for unicast traffic between IPv6/IPv4 nodes across the IPv4 Internet

• 6to4 treats the IPv4 Internet as a single link

What Is Teredo?

When Teredo is behind a restricted NAT, initial communication involves several additional steps

Teredo Server 2Teredo Server 1

TeredoClient A

Teredo Client B

Restricted NAT

Restricted NAT

XIPv4 Internet

X

1

2

3

5

4

Bubble packet to Teredo Client B1

Bubble packet to Teredo Server 22

Forwarded bubble packet to Teredo Client B3

Bubble packet to Teredo Client A4

Direct packet to Teredo Client B5

Teredo: Restricted NAT

Establish a Teredo server1

Establish communications between Teredo clients3

Discover the kind of NAT running at a given host2

How Teredo works:

IPv6-onlyhost

Teredo relay

NAT

Teredo client

IPv6 traffic

IPv6 over IPv4 traffic

X

NAT

IPv6 InternetIPv4 Internet

X

Teredo server

Teredo host-specificrelay

IPv6 or IPv6 over IPv4 traffic

Components of Teredo Tunneling

• Address-assignment and automatic tunneling technology for unicast traffic between IPv6/IPv4 nodes located behind one or more IPv4 NATs on the IPv4 Internet

• 6to4 relies on public IPv4 address and IPv6 router functionality in an edge device

• Automatically adjusts behavior based on the type of the local NAT

What Is PortProxy?

PortProxy is a component that allows the proxying of the following traffic:

• IPv4 to IPv4: TCP traffic to an IPv4 address is proxied to TCP traffic to another IPv4 address

• IPv4 to IPv6: TCP traffic to an IPv4 address is proxied to TCP traffic to an IPv6 address

• IPv6 to IPv6: TCP traffic to an IPv6 address is proxied to TCP traffic to another IPv6 address

• IPv6 to IPv4: TCP traffic to an IPv6 address is proxied to TCP traffic to an IPv4 address

Lab A: Configuring an ISATAP Router

• Exercise 1: Configuring a New IPv6 Network and Client

• Exercise 2: Configuring an ISATAP Router to Enable Communication Between an IPv4 Network and an IPv6 Network

Estimated time: 30 minutes

Logon information

Virtual machines6421B-NYC-DC16421B-NYC-RTR6421B-NYC-CL2

User name Contoso\Administrator

Password Pa$$w0rd

Lab Scenario

Contoso has decided to begin the process of migrating their network to IPv6. Your initial task is to prove the principle of the migration by configuring a single client computer for IPv6.

Lab Review

•What does an ISATAP router allow an IPv6/IPv4 hybrid node to do?

•What do you need to define on the DNS server for an ISATAP router to function properly?

•What does advertising a prefix do when you are defining a prefix in the IPv6 router?

Lesson 5: Transitioning from IPv4 to IPv6

•Discussion: Considerations for Migrating from IPv4 to IPv6

• Process for Transitioning to Native IPv6

Discussion: Considerations for Migrating from IPv4 to IPv6

How might applications be affected?What kind of network infrastructure and network services need to be in place?What devices need to be upgraded?

15 minutes

Process for Transitioning to Native IPv6

Applications1

Upgrade hosts to IPv6/IPv4 nodes3

DNS infrastructure 2

Convert IPv6/IPv4 nodes to IPv6-only nodes5

Upgrade routing infrastructure for native IPv6 routing4

Lesson 6: Troubleshooting IPv6

•Methods Used to Troubleshoot IPv6

•Verifying IPv6 Connectivity

•Verifying DNS Name Resolution for IPv6 Addresses

•Verifying IPv6-based TCP Connections

Methods Used to Troubleshoot IPv6

Verify IPv6 connectivity

Verify IPv6-based TCP connections

Verify DNS name resolution for IPv6 addresses

Verifying IPv6 Connectivity

Verify configuration (IPconfig and netsh)

Verify reachability

Manage configuration (netsh)

Check packet filtering

View and manage the IPv6 routing table (route print)

Verify router reliability (pathping)

Verifying DNS Name Resolution for IPv6 Addresses

Verify DNS configuration

Test DNS name resolution with the Ping tool

Display and flush the DNS client resolver cache

Use the Nslookup tool to view DNS server responses

Verifying IPv6-based TCP Connections

Check for packet filtering

Verify TCP connection establishment

Lab B: Converting the Network to Native IPv6

• Exercise 1: Transitioning to a native IPv6 network

Estimated time: 30 minutes

Logon information

Virtual machines6421B-NYC-DC16421B-NYC-RTR6421B-NYC-CL2

User name Contoso\Administrator

Password Pa$$w0rd

Lab Scenario

The pilot went well. Your manager has asked you to convert the network to IPv6. Your task is to disable ISATAP and enable native IPv6 routing. For this project, you must transition to a native IPv6 Network.

Lab Review

•Why must you disable the ISATAP router when transitioning to IPv6?

Module Review and Takeaways

•Review Questions

• Tools