2. • 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

3. 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

4. Internet Protocol
Transports a datagram from source host to
destination, possibly via several intermediate nodes
(“routers”)
Service is:
Unreliable: Losses, duplicates, out-of-order delivery
Best effort: Packets not discarded capriciously,
delivery failure not necessarily reported
Connectionless: Each packet is treated independently
Data gram: consist of variable header and a variable
data field

5. 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

8. IPv6 availability
Generally 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

9. IP v6 - Version Number
IP v 1-3 defined and replaced
IP v4 - current version
IP v5 - streams protocol
IP v6 - replacement for IP v4
During development it was called IPng
Next Generation

10. 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 Internet
Extended use of TCP/IP
Single address per host
Requirements for new types of service

11. 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 Internet
Extended use of TCP/IP
Single address per host
Requirements for new types of service

14. IPv6 Header
VERS 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)

15. IPv6 Header Fields
VERS: 6 (IP version number)
Priority: will be used in congestion control
Flow 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.

16. IPv6 Header Fields
Next 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).

17. IPv6 Addresses
128 bits long
Assigned to interface
Single interface may have multiple unicast addresses
Three types of address
ADVANTAGE
• Larger add. Space
• Better header format
• New option
• Supported more security and resource allocation

18. Types of address
Unicast
Single interface
Delivery to single interface
Eg. Global unicast add , link local add, site local add
Anycast
Set of interfaces (typically different nodes)
Delivered to any one interface
the “nearest”
Multicast
Set of interfaces
Delivered to all interfaces identified
Commnly used scope include link local add, site local

19. Multicasting
Addresses that refer to group of hosts on one or more
networks
Uses
Multimedia “broadcast”
Teleconferencing
Database
Distributed computing
Real time workgroups

20. Example
Config
20

21. Broadcast and Multiple Unicast
Broadcast a copy of packet to each network
Requires 13 copies of packet
Multiple Unicast
Send packet only to networks that have hosts in group
11 packets

22. IPv4-Mapped IPv6 Address
IPv4-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.

23. Works with DNS
An 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.

24. IPv4-Compatible IPv6 Address
An 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.

25. 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.

26. Auto-configuration in IPv6
Link-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.

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