Tài liệu ADM389 IPv6 docx

IP Address Allocation History1981 - IPv4 protocol published NAT network address translation CIDR classless inter-domain routing plus some address reclamation Theoretical limit of 32-bit

Make a (brief) case for IPv6 (level 200) Give you a crash-course on the main aspects of the protocol (level 300)

Explain the available technology support including migration strategies (level 300)

Why IPv6?

IP Address Allocation History

1981 - IPv4 protocol published

NAT (network address translation)

CIDR (classless inter-domain routing)

plus some address reclamation

Theoretical limit of 32-bit space: ~4 billion devices

Practical limit of 32-bit space: ~250 million devices (RFC 3194)

Running Out of Addresses

Even if every company used only 1 address by fully utilising NATs (Network Address Translation)…

…we would be out of addresses in the next 3-5 years

“Slower that Y2K problem, but a surer one”

More IPv4 Pain

Argh, NATs 

Peer-to-peer is difficult NAT security record is dubious Management is a pain

Security is an optional add-on QoS (Quality of Service) is rare and not real-time Routing tables too large and process slow

Mobility is a pain

But peer-to-peer mobility is the future of Internet

Device autoconfiguration is rare

DHCP & address ownership does not work across organisational boundaries

Using external agents for autoconfiguration is a non-starter

US versus ROW

US accounts for 90% of address allocation

Some universities in US have more allocated addresses than the whole of Asia

The so-called, in US, “Rest of the World” is hardly an even partner

Reliance on American organisations may be politically difficult, at times, for large or

governmental Internet projects Gives US an unwelcome monopoly power

6 Benefits of IPv6

Address depletion solved International misallocation solved End-to-end communication restored Scoped addresses & address selection More efficient forwarding

Built-in security and mobility

Who’s Doing IPv6?

More places than you would think!

Japanese city of Kyoto (now)JANET (Joint Academic Network) in UK

US Deparment of Defence

June 13 th 2003 decision made by Pentagon ( http://story.news.yahoo.com/news?tmpl=story&cid=1509&ncid

=738&e=6&u=/afp/20030613/tc_afp/us_military_internet )

Planning and preparation in 2003-4 Transition in 2005

Completion in 2008

Crash Course on IPv6

Features of IPv6

New header formatLarge address spaceEfficient and hierarchical addressing and routing infrastructure

Stateless and stateful address configurationBuilt-in security

Better support for QoSNew protocol for neighboring node interactionExtensibility

Feature IPv4 IPv6

Address length 32 bits 128 bits

IPSec support Optional Required

Fragmentation Hosts and routers Hosts only

Packet size 576 bytes 1280 bytes

Link-layer address resolution ARP (broadcast) Multicast Neighbor

Discovery Messages Multicast membership IGMP Multicast Listener

Discovery (MLD) Router Discovery Optional Required

Configuration Manual, DHCP Automatic, DHCP

DNS name queries Uses A records Uses AAAA

records DNS reverse queries Uses IN-ADDR.ARPA Uses IP6.INT

LAN segment

Link

Subnet

Network

The IPv6 Address Space

128-bit address space

2128 possible addresses

340,282,366,920,938,463,463,374,607,431,768,211,456

addresses (3.4 x 10 38 ) 6.65 x 10 23 addresses per square metre of Earth’s surface

128 bits were chosen to allow multiple levels of hierarchy and flexibility in designing

hierarchical addressing and routingTypical unicast IPv6 address:

64 bits for subnet ID, 64 bits for interface ID

IPv6 Address Syntax

IPv6 address in binary form:

0010000111011010000000001101001100000000000000000010111100111011 0000001010101010000000001111111111111110001010001001110001011010

Divided along 16-bit boundaries:

FE80:0:0:0:2AA:FF:FE9A:4CA2 becomes FE80::2AA:FF:FE9A:4CA2

IPv6 Prefixes

Prefix is the part of the address where the bits have fixed values or are the bits of a route or subnet identifier

IPv6 subnets or routes always uses

Types of IPv6 Addresses

No more broadcast addresses

Unicast IPv6 Addresses

Aggregatable global unicast addresses Link-local addresses

Site-local addresses Special addresses Compatibility addresses NSAP addresses

Aggregatable Global Unicast Addresses

Top-Level Aggregation ID (TLA ID) Next-Level Aggregation ID (NLA ID) Site-Level Aggregation ID (SLA ID) Interface ID

Topologies Within Global Addresses

Public Topology Site Topology Interface ID

Local-Use Unicast Addresses

Link-Local Addresses

Format Prefix 1111 1110 10

FE80::/64 prefix

Used for local link only

Single subnet, no routerAddress autoconfigurationNeighbor Discovery

1111 1110 10 Interface ID

10 bits 64 bits

000 000

54 bits

Site-Local Addresses

Format Prefix 1111 1110 11

FEC0::/48 prefix for site

Used for local site only

Replacement for IPv4 private addressesIntranets not connected to the InternetRouters do not forward site-local traffic outside the site

NSAP Addresses

0000001 NSAP-mapped address

7 bits 121 bits

Special IPv6 Addresses

IPv6 Header

Upper Layer Protocol Data Unit Payload

IPv6 Packet

Extension Headers

Structure of an IPv6 Packet

VersionTraffic ClassFlow LabelPayload Length

Next Header

Hop LimitSource AddressDestination Address

Structure of the IPv6 Header

Values of the Next Header Field

Besides using DHCP, you can always autoconfigure an address

Check twice it is not a duplicate

Talk to routers and neighbours to be sure

Addresses expire, no concept of globally permanent addresses

Temporary Address Interface Identifiers

Random IPv6 interface identifier

Prevent identification of traffic regardless of the prefix - anonymity

Initial value based on random number Future values based on MD5 hash of history value and EUI-64-based interface identifier

Result is a temporary address

Generated from public address prefixes using stateless address autoconfiguration

Changes over time

Multiple Addresses on a Node

Unlike in IPv4, a node always has multiple addresses

Link-local, site-local*, global etc.

It is the job of the protocol stack on each node

to decide which address to use depending on who are we talking to

Greatly simplifies the job of routers, of course

This is in the spirit of peer-to-peer and distribution of processing power, by the way

Notify it where you are

It will tunnel things to youYou can do Binding Updates with anyone you correspond to establish a direct path

Result: no loss of a session while you roam!

Technology Support and Migration Strategy

Coexistence and Migration

The transition from IPv4 to IPv6 will take years

Some hosts will use IPv4 indefinitely Migration is the long term goal, coexistence in the interim

Transition criteria:

Existing IPv4 hosts can be upgraded at any time independent of the upgrade of other hosts or routers New hosts using only IPv6 can be added at any time without dependencies on other hosts or routing infrastructure

Existing IPv4 hosts with IPv6 installed can continue to use their IPv4 address and do not need additional addresses Little preparation is needed to upgrade existing IPv4 nodes

to IPv6 or to deploy new IPv6 nodes

Application Layer

Transport Layer (TCP/UDP)

IPv6

Network Interface Layer

IPv4

Dual IP Layer Architecture

Application Layer

TCP/UDP

IPv6

Network Interface Layer

TCP/UDP

IPv4

Dual Stack Architecture

Windows Sockets applications

IPv4 (Tcpip.sys)

Network adapter drivers

IPv6 (Tcpip6.sys)

TDI

NDIS

Windows Sockets

Windows Sockets components

Windows Server 2003 IPv6

WS2003 IPv6 Features

Basic stack support

Only Ethernet and FDDI (no Token Ring or PPP)

No Microsoft-specific IPv4 enhancements (from W2K)

6to4, ISATAP, 6over4, PortProxy Temporary addresses

DNS support (dynamic AAAA and reverse) IPSec6 support

Generically incompatible with IPSec for IPv4

No ESP for data encryption, no IKE for SA negotiation –use ipsec6.exe for manual configuration of SAs

Address selection and autoconfiguration Can be a static router

Site prefixes in router advertisements

Application Support in WS2003

Internet Explorer Telnet client

FTP client Internet Information Services, version 6 File and print sharing

Windows Media Services Network Monitor

SNMP MIB support

Application Programming Interfaces in WS2003

Windows Sockets (WinSock) Remote Procedure Call (RPC) Internet Protocol Helper (IPHelper) Win32 Internet Extensions (WinInet) NET Framework

IPv6-enabled Utilities

Ipconfig Route Ping Tracert Pathping Netstat

IPv6 Command Line Utilities

Netsh.exe

interface ipv6interface ipv6 6to4interface ipv6 isatapinterface portproxy

Ipsec6.exe

Installing & Configuring IPv6

Install

Add the “Microsoft TCP/IP version 6”

protocol when configuring the properties of

a LAN connection in Network ConnectionsExecute netsh interface ipv6 install at a command prompt

Configure

IPv6 is self-configuringFor manual configuration, use commands

in the netsh interface ipv6 context

Migrating to IPv6

1 Upgrade your applications to be

independent of IPv4 or IPv6

2 Update the DNS infrastructure to support

IPv6 addresses and PTR records

3 Upgrade hosts to IPv4/IPv6 nodes

4 Upgrade routing infrastructure for native

IPv6 routing

5 Convert IPv4/IPv6 nodes to IPv6-only

nodes

Prepare your infrastructure over the next year, if possibleContact the experts for help 

www.ip426.com at your service

in association with www.ip426.com

Ask The Experts

Get Your Questions Answered

I will be at the Ask The Experts stand on

Friday from 12:00 till 14:00 waiting for

Suggested Reading & Resources

“Understanding IPv6”, Joseph Davies,

Microsoft Press, ISBN 0-7356-1245-5

Available (limited copies) on Microsoft Press stand near the conference rooms during TechEd 2003 at a discount!

www.microsoft.com/ipv6 www.ipv6forum.org

www.ip426.com

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© 2003 Microsoft Corporation & Project Botticelli Ltd All rights reserved This presentation is for informational purposes only MICROSOFT AND PROJECT BOTTICELLI MAKE NO WARRANTIES, EXPRESS OR IMPLIED, IN THIS SUMMARY.