Internet Protocol Version 6 - Studio Reti

IPv6 - 1 Copyright: see page 2

Internet Protocol Version 6

Silvano GAIhttp://www.ip6.com

Mario BALDIhttp://staff.polito.it/mario.baldi


Nota di CopyrightThis set of transparencies, hereinafter referred to as slides, is protected by copyright laws and provisions of International Treaties. The title and copyright regarding the slides (including, but not limited to, each and every image, photography, animation, video, audio, music and text) are property of the authors specified on page 1.The slides may be reproduced and used freely by research institutes, schools and Universities for non-profit, institutional purposes. In such cases, no authorization is requested.Any total or partial use or reproduction (including, but not limited to, reproduction on magnetic media, computer networks, and printed reproduction) is forbidden, unless explicitly authorized by the authors by means of written license.Information included in these slides is deemed as accurate at the date of publication. Such information is supplied for merely educational purposes and may not be used in designing systems, products, networks, etc. In any case, these slides are subject to changes without any previous notice. The authors do not assume any responsibility for the contents of these slides (including, but not limited to, accuracy, completeness, enforceability, updated-ness of information hereinafter provided). In any case, accordance with information hereinafter included must not be declared.In any case, this copyright notice must never be removed and must be reported even in partial uses.


Why a new IPInternet: the real point of contactAn addresses space wide enough

Multicast and Anycast AddressesTo unify Internet and IntranetFor a better use of LANSecurityPolicy RoutingPrioritization of traffic (Classes of Service)Plug and playMobilitySimple transition from IPv4 to IPv6


IP and B-ISDN

IP + RSVP

ATM

Satellite

FrameRelay

CATV


The Future

Residential

$$Electronic Commerce

Mobile

Call Center

Education

The Internet

Office


Full-Service Intranet

E-mail

NOSPrint E-Mail

Directory

File

Full-ServiceIntranetPrint E-MailDirectory

File

NOSPrint

DirectoryFile

Intranet

NetworkManagement

E-MailDirectory

File

IntranetE-Mail

NetworkManagement

File

Network Management

1994–1996

1997–1998

1999–2000Source: Forrester Research, Inc.


How many IPv6 Addresses1.000.000 milliards of computers in networkEfficiency:

Real CasesH variation is from 0.22 to 0.26

68 bit are requested in the worst case

H = log (addresses number)bit number

10


SyntaxHexadecimal notation: 8 natural numbers separated by “:”

FEDC:BA98:0876:45FA:0562:CDAF:3DAF:BB011080:0000:0000:0007:0200:A00C:3423:A390

There are simplifications:Leading zeroes can be omitted

1080:0:0:7:200:A00C:3423Groups of zeroes can be replaced by “::”

1080::7:200:A00C:3423

IPv4 compatible addresses are written as:0:0:0:0:0:0:A00:1::A00:1::10.0.0.1


PrefixesThe concept of Netmask no longer existsIt is substituted by the concept of “Prefix”A prefix is identified by appending “/N” to the sequence of hexadecimal digits, where N is the prefix length in bitsExample:

FEDC:0123:8700::/36 indica il prefisso111111101101110000000001001000111000

Subnet prefix Interface address

128 - n bitn bit


LAN BroadcastBroadcast RemovalMulticast instead of Broadcast

LAN OptimizationMore intelligent Network Cards


Address AssignmentUnifying Internet and Intranets

global addresseslocal addresses

Compatible AddressesIPv4IPXOSI NSAP


Best Effort ?

Application(e.g., videoconference)

Layer 3 Protocol(e.g., IP + RSVP)

Lower Layer(e.g., ATM, SONET, Optical)

Request ofQoS

Request ofQoS

QoS Granted

QoS Granted

The Concept of Flow in IPv6


SecurityIntegral Part of IPv6

Legal problemsexportuse

AuthenticationPrivacy } Cryptography


RoutingIn IPv4

ClassfulCIDR (Classless Inter Domain Routing)Extraordinary Increase of Routing Tables

In IPv6ClasslessProvider Based Addresses

Efficient aggregationPolicy Routing


PriorityTraffic Differentiation as a function of priority

Class of Service (CoS)Data trafficReal time traffic


Plug and PlayTo satisfy

Dentist OfficeThousand computers on the dock

Statelessno server

Statefullserver DHCP


MobilityIn 2007 there will be 20-40 millions of mobile users in USALaptop + PCMCIA card + cellular network

roaminghandoff


TransitionDual-stack ApproachTunneling6-BoneThe doomsday


CandidatesTUBA (TCP and UDP over Bigger Addresses)

from OSI CLNP (ISO 8473)NSAP settled on 20 octects

SIP (Simple IP)An IP with 64 bit addresses

IPAE (IP Address Encapsulation)IP in IP (two IP layers)

1 IP for world-wide interconnections1 IP for local interconnections


CandidatesPIP

A New Approach to:policy routingmobility

SIPP (SIP Plus)SIP and PIP merge

IPv6based on SIPP128 bit of address


How to chooseArchitecture Simplicity

In every thing you reach the perfection

not when you have no more to add,

but when you have no more to take away.

Antoine de Saint-Exupery

from “Le Petit Prince”


So, What Went Wrong?Nothing, but IPv4 is hanging on!

Intranet and application proxiesNAT - Network Address TranslationDHCP - Dynamic Host Configuration ProtocolIPsecMobility support


Terminologynode

a device implementing IPv6router

a routing capacity nodehost

each node which is not a routerlink

Data Link level (level 2) communication channel; link example are Ethernet, PPP, X.25, Frame Relay e ATM, or tunnel on different protocol

neighborsnodes connected to the same link;

interfaceNode-link interconnection device


Router

Node

To otherNetwork

X.25PSDN

IPv6 Network Architecture


SubnetworkFormer concept of IPv4Subnetwork correspondence with physical network

more subnet allowed on the same physical network

Subnet identified by a prefixa 128 bit address + number of significant bits from the left side


RouterHost

Router Advertisement

Router Solicitation

Routing Redirect

Neighbor Advertisement

Neighbor Solicitation

Neighbor Discovery


MAC DSAP

MAC SSAP

86DD

FCS

PDU - IPv6

(a)

MAC DSAP

MAC SSAP

Length AA - AA

FCS

PDU - IPv6

00-00-0003

86DD

(b)

IPv6 and LAN


IPv6 Packet: Example

00 A0 24 6F B7 02 08 00 2B B5 A7 A8 86 DD 6C 0000 00 00 40 3A FC 5F 00 30 00 84 FA 5A 00 00 0000 00 00 00 00 05 5F 15 50 00 82 C0 0E 00 00 BD00 A0 24 6F B7 02 81 00 C5 E0 A7 00 0B 00 49 F4AE 32 8D D4 0B 00 08 09 0A 0B 0C 0D 0E 0F 10 1112 13 14 15 16 17 18 19 1A 1B 1C 1D 1E 1F 20 2122 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 3132 33 34 35 36 37 37 62 3D DA

Ethernet destination address

Ethernet sourceaddress

ProtocolType

ICMPv6packet

IPv6Header


IPv4 Header00 4 8 16 19 24 31

Vers. Hlen Serv. Type Total Length

Identification Flags Fragment Offset

Time To Live Protocol Header Checksum

Source IP Address

Destination IP Address

Options PAD


IPv6 HeaderSimple and fixed lenght (40 octets) structure

8 octets with 6 fieldsSource Address (16 octets)Destination Address (16 octets)

Some features of the IPv4 header have been removed:

header checksumfragmentationoptions (e.g. source routing)


IPv6 HeaderVersion Priorit. Flow Label

Payload Length Next Header Hop Limit

Source Address

Destination Address


IPv6Significant Changes

IP ProtocolARP ProtocolICMP ProtocolIGMP Protocol

UpgradesTCP and UDPSocketsDNSRIP and OSPFBGPand IDRP


Main protocol changesNew 128 bit addresses must be included

TCP uses them to identify the connectionUDP calculates the checksumThe socket interface must be changedDNS must be changed


DNS Changesaddress definition IPv4HOST1.POLITO.IT IN A 130.192.253.252

address definition IPv6HOST1.POLITO.IT IN AAAA 4321:0:1:2:3:4:567:89ab

reverse definition IPv4252.253.192.130.IN-ADDR.ARPA. PTR HOST1.POLITO.IT

reverse definition IPv6b.a.9.8.7.6.5.0.4.0.0.0.3.0.0.0.2.0.0.0.1.0.0.0.

0.0.0.0.1.2.3.4.IP6.INT. PTR HOST1.POLITO.IT


Address AssignmentThe Continental Aggregation yields limited results

topology is chosen by providersit is not a good strategy to assign addresses to users

In order for the CIDR to work, addresses must be assigned to providers that:

divide addresses during the assignment phaseaggregate them during the announcement phase

IPv6 will have only provider based addresses

easy renumbering


BibliographyS. Bradner, A. Mankin, “RFC 1752: The Recommendation for the IP Next Generation Protocol,” January 1995 IAB, IESG, “RFC 1881: IPv6 Address Allocation Management,” December 1995S. Deering, R. Hinden, “RFC 1883: Internet Protocol, Version 6 (IPv6) Specification,” December 1995R. Hinden, S. Deering, “RFC 1884: IP Version 6 Addressing Architecture,” December 1995A. Conta, S. Deering, “RFC 1885: Internet Control Message Protocol (ICMPv6),” December 1995S. Thomson, C. Huitema, “RFC 1886: DNS Extensions to support IP version 6,” December 1995Y. Rekhter, T. Li, “RFC 1887; An Architecture for IPv6Unicast Address Allocation,” December 1995R. Hinden, J. Postel, “RFC 1897: IPv6 Testing Address Allocation,” January 1996


Bibliography R. Hinden, J. Postel, “RFC 1897: IPv6 Testing Address Allocation,” January 1996.R. Elz, “RFC 1924: A Compact Representation of IPv6 Addresses,” April 1996.R. Gilligan, E. Nordmar, “RFC 1933: Transition Mechanisms for IPv6 Hosts and Routers,” April 1996.Narten, E. Nordmark, W. Simpson, “RFC 1970: Neighbor Discovery for IP Version 6 (Ipv6),” August 1996. Thomson, T. Narten, “RFC 1971: IPv6 Stateless AddressAutoconfiguration,” August 1996. Crawford, “RFC 1972: A Method for the Transmission of IPv6 Packets over Ethernet Networks,” August 1996. M. Crawford, "RFC 2019: Transmission of IPv6 Packets Over FDDI," October 1996.D. Haskin, E. Allen, "RFC 2023: IP Version 6 over PPP," October 1996.D. Mills, "RFC 2030: Simple Network Time Protocol (SNTP) Version 4 for IPv4, IPv6 and OSI," October 1996.

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Internet Protocol Version 6 - Studio Reti