IPv4 and IPv6 are different versions of the Internet Protocol. IPv4 uses 32-bit addresses which limits the available number of addresses to around 4 billion, while IPv6 uses 128-bit addresses allowing for a vast number of available addresses. Some techniques were used to extend IPv4 such as subnetting and NAT, but IPv6 was developed to provide a long-term solution and overcome IPv4's scaling limitations. IPv6 improves upon IPv4 in areas such as efficiency, security, auto-configuration, and header structure. Widespread adoption of IPv6 has been slowed due to compatibility issues and costs of upgrading systems.

1. IPv4 vs IPv6
Alishiram Alakparov, Rasul Karimov, Mammad Hajili

2. OSI and TCP/IP network
models
• Open Systems
Interconnection Reference
Model
• Splits communication
system into seven layers
• Each layer performs their
task and passes the data to
the next layer

3. What is IP address?
• IP stands for Internet Protocol
• IP is a Network Layer Protocol
• IP by itself is something like the postal system.
• It allows you to address a package and drop it in the system, but
there's no direct link between you and the recipient.
• IP specifies the format of packets, also called datagrams, and the
addressing scheme. Most networks combine IP with a higher-level
protocol called Transmission Control Protocol (TCP), which establishes
a virtual connection between a destination and a source.

4. What is IP?
• Each network layer has units called datagram
• Datagram of network layer is called packet which consists of:
• Header
• Data (payload)

5. Purpose of IP
• Need a standard means of communication between devices
• Can’t communicate if speaking two different languages
• IP includes a set of rules that process the idea of unreliable packet
delivery.
• How hosts and routers should process packets
• How & when error messages should be generated
• The Conditions under which packets can be discarded.

6. Brief history of IPv4
• Internet Protocol version 4 (IPv4) is the fourth version of the Internet
Protocol
• It was deployed for production in the ARPANET in 1983.
• At the start developer of IP didn’t realize the potential of Internet
• It is still considered the main Internet Protocol and carried 94% of
Internet traffic in 2014
• With 32 bit address space it allows 4 billion (4,294,967,296) unique
address space
• However certain limitation has already arrived.

7. IPv4 Exhaustion reports
• IANA Unallocated Address Pool Exhaustion(The Internet Assigned
Numbers Authority): 03-Feb-2011
• Projected RIR(Regional Internet Registry) Address Pool Exhaustion
Dates:
RIR Responsible Region Exhaustion Dateri
APNIC Asia-Pacific 19-Apr-2011
RIPE NCC Europe 14-Sep-2012
LACNIC Latin America and Caribbean 10-Jun-2014
ARIN America 24 Sep-2015
AFRINIC Africa 09-Dec-2018

8. Brief history of IPv6
• Internet Protocol version 6 (IPv4) is the sixth version of the Internet
Protocol
• Internet Engineering Task Force (IETF) initiated as early as in 1994, the
design and development of a suite of protocols and standards now
known as Internet Protocol Version 6.
• It was aimed to solve the problems associated with IPv4
• With 128 bit address space it allows 3.4×10^38 or 340 undecillion
unique address space
• More and more devices now supports IPv6 and 11.2% of all websites
now uses IPv6 including Google, Facebook, Wikipedia and etc.

9. How IPv4 works
• IPv4 represented in Binary formation
• Each 4 bytes are called octets. The maximum value for octet is 255 in decimal

10. How IPv6 works
• IPv4 represented in Hexadecimal formation (0-F)
• 8 16 bit section. Each 4 bit for one hexadecimal value.

11. How to solve limitation problems in IPv4?
Subnetting
• By creating subnets from single IP address, we partially solve shortage
problem

12. How to solve limitation problems in IPv4?
NAT
• Devices within network uses private IP address and when that device
need to communicate with other device outside internal network it is
assigned public IP within pool either statically or dynamically.
• It is carried out manually or with DHCP
• Disadvantages of this method is lack of peer to peer communication
and security

13. How to solve limitation problems in IPv4?
PAT

14. What are differences in packetheader?

15. Header fields in IPv6
• Version: A four-bit field for the IP version number (0x06).
• Traffic Class: An 8-bit field that identifies the major class of the packet
content (for example, voice or video packets). The default value is 0,
meaning it is ordinary bulk data (such as FTP) and requires no special
handling
• Flow Label: A 20-bit field used to label packets belonging to the same
flow (it identifies protocols like UDP or TCP/IP). The flow label is
normally 0 (flows are detected in other ways)
• Payload Length: A 16-bit field giving the length of the packet in bytes,
excluding the IPv6 header (no need for header length since it is fixed
with 40 bytes)

16. Header fields in IPv6
• Next Header: An 8-bit field giving the type of header immediately
following the IPv6 header (this serves the same function as the
Protocol field in IPv4).
• Hop Limit: An 8-bit field set by the source host and decremented by 1
at each router. Packets are discarded if Hop Limit is decremented to
zero (this replaces the IPv4 Time To Live field). Generally,
implementers choose the default to use, but values such as 64 or 128
are common.(This name makes much more sense than TTL)

17. Subnetting in IPv6
• The allocation of IPv6 addresses to specific RIRs starts around a /23.
From these address blocks the RIRs allocate and assign IPv6 addreses
to ISPs. Addresses assigned this way typically start around /32). For an
end site (customer site), the general rule as of this writing is to
allocate somewhere between a /48 and a /56 and to use the last 64
bits of the range for host ID. What this means is that an end
organization is given between 8 to 16 bits of subnetting space (from
the 49th bit to 64th bit, or from the 57th bit to 64th bit) for internal
address organization.
• By doing so Regional communication speed might increase
dramatically

19. Advantages of IPv6 over IPv4
• More efficient routing. IPv6 routers no longer have to fragment packets, an
overhead-intensive process that just slows a network down.
• Built-in Quality of Service (QoS) that distinguishes delay-sensitive packets
• Elimination of NAT to extend address spaces. IPv6 increases the IPv4
address size from 32 bits (about 4 billion) to 128 bits (enough for every
molecule in the solar system).
• Network layer security built-in (IPsec). Security, always a challenge in IPv4,
is an integral part of IPv6.
• Stateless address auto configuration (SLAAC) for easier network
administration. Many IPv4 installs were complicated by manual default
router and address assignment. IPv6 handles this in an automated fashion
• Improved header structure with less processing overhead. Many of the
fields in the IPv4 header were optional and used infrequently. IPv6
eliminates these fields.

20. So what prevents us from switching to IPv6?
• ISP are not willing to:
• To refurbish their system to support both IPv4 and IPv6 since it’s expensive
• To give up control of traffic which goes through NAT
• Backward compatibility is not supported
• Trying to access a website using IPv6 from IPv4 system will not work
• But some new devices already implements IPv6