• Internet Protocol version 4 (IPv4, or just “IP”)– First developed for the original Internet (ARPANET) in spring

1978– Deployed globally with growth of the Internet– Total of 4 billion IP addresses available– Well entrenched and used by every ISP and hosting

company to connect customers to the Internet– Allocated based on documented need

• Internet Protocol version 6 (IPv6)– Design started in 1993 when IETF forecasts showed IPv4

depletion between 2010 and 2017– Completed, tested, and available for production since 1999– Total of

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

– Used and managed similar to IPv4

IP version

IPv4 IPv6

Deployed 1981 1999

Address Size

32-bit number 128-bit number

Address Format

Dotted Decimal Notation: 192.0.2.76

Hexadecimal Notation: 2001:0DB8:0234:AB00:0123:4567:8901:ABCD

Number of Addresses

232 = 4,294,967,296 2128 = 340,282,366,920,938,463,463,374,607,431,768,211,456

Formate/ Length

not Yes

Internet Protocol Transports a datagram from source host to

destination, possibly via several intermediate nodes (“routers”)

Service is:Unreliable: Losses, duplicates, out-of-order

deliveryBest effort: Packets not discarded capriciously,

delivery failure not necessarily reportedConnectionless: Each packet is treated

independentlyData gram: consist of variable header and a

variable data field

IP Datagram Header header and data

VERS HLEN TOS TOTAL LENGTH

IDENTIFICATION FLAG FRAGMENT OFFSET

TTL PROTOCOL CHECKSUM

SOURCE ADDRESS

DESTINATION ADDRESS

OPTIONS (if any) + PADDING

0 4 8 16 19 31

IPv6 availabilityGenerally available with (new) versions of

most operating systems.

BSD, Linux 2.2 Solaris 8

An option with Windows 2000/NT

Most routers can support IPV6

IP v6 - Version NumberIP v 1-3 defined and replacedIP v4 - current versionIP v5 - streams protocolIP v6 - replacement for IP v4

During development it was called IPng Next Generation

Why Change IP?Address space exhaustion

Two level addressing (network and host) wastes space

Network addresses used even if not connected to Internet

Growth of networks and the InternetExtended use of TCP/IPSingle address per host

Requirements for new types of service

Why Change IP?Address space exhaustion

Two level addressing (network and host) wastes space

Network addresses used even if not connected to Internet

Growth of networks and the InternetExtended use of TCP/IPSingle address per host

Requirements for new types of service

IPv6 HeaderVERS 4bit PRIO 4b

Hop Limit 8b

Flow Label 24b

Payload Length 16b Next Header 8b

1 byte1 byte 1 byte 1 byte

6 for IPv6

Source Address (128 bits - 16 bytes)

Dest. Address (128 bits - 16 bytes)

IPv6 Header FieldsVERS: 6 (IP version number)Priority: will be used in congestion controlFlow Label: experimental - sender can

label a sequence of packets as being in the same flow.

Payload Length: number of bytes in everything following the 40 byte header.

IPv6 Header FieldsNext Header is similar to the IPv4 “protocol”

field - indicates what type of header follows the IPv6 header.

Hop Limit is similar to the IPv4 TTL field (but now it really means hops, not time).

IPv6 Addresses128 bits longAssigned to interfaceSingle interface may have multiple unicast

addressesThree types of address

ADVANTAGE • Larger add. Space• Better header format• New option• Supported more security and resource allocation

Types of addressUnicast

Single interfaceDelivery to single interfaceEg. Global unicast add , link local add, site local add

AnycastSet of interfaces (typically different nodes)Delivered to any one interfacethe “nearest”

MulticastSet of interfacesDelivered to all interfaces identifiedCommnly used scope include link local add, site local

MulticastingAddresses that refer to group of hosts on one

or more networksUses

Multimedia “broadcast”TeleconferencingDatabaseDistributed computingReal time workgroups

Example Config

20

Broadcast and Multiple UnicastBroadcast a copy of packet to each network

Requires 13 copies of packetMultiple Unicast

Send packet only to networks that have hosts in group

11 packets

IPv4-Mapped IPv6 AddressIPv4-Mapped addresses allow a host that

support both IPv4 and IPv6 to communicate with a host that supports only IPv4.

The IPv6 address is based completely on the IPv4 address.

Works with DNSAn IPv6 application asks DNS for the address

of a host, but the host only has an IPv4 address.

DNS creates the IPv4-Mapped IPv6 address automatically.

Kernel understands this is a special address and really uses IPv4 communication.

IPv4-Compatible IPv6 AddressAn IPv4 compatible address allows a host

supporting IPv6 to talk IPv6 even if the local router(s) don’t talk IPv6.

IPv4 compatible addresses tell endpoint software to create a tunnel by encapsulating the IPv6 packet in an IPv4 packet.

Mobility Support in IPv6

Mobile computers are becoming commonplace.Mobile IPv6 allows a node to move from one link to

another without changing the address.Movement can be heterogeneous, i.e., node can move

from an Ethernet link to a cellular packet network.Mobility support in IPv6 is more efficient than

mobility support in IPv4.There are also proposals for supporting micro-

mobility.

Auto-configuration in IPv6Link-local prefix concatenated with 64-bit MAC

address. (Autonomous mode)

Prefix advertised by router concatenated with 64-bit MAC address. (Semi-autonomous mode.)

DHCPng (for server modes)Can provide a permanent address (stateless mode)Provide an address from a group of addresses, and

keep track of this allocation (stateful mode)Can provide additional network specific information.Can register nodes in DNS.

Big users: Germany (33%), EU (24%), Japan (16%), Australia (16%)