Saturday, 5 May 2012

What is The Difference Between IPv6 and IPv4?

What is Internet Protocol -- IP?

IP (short for Internet Protocol) specifies the technical format of packets and the addressing scheme for computers to communicate over a network. 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.

IP by itself can be compared to 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. TCP/IP, on the other hand, establishes a connection between two hosts so that they can send messages back and forth for a period of time.

There are currently two version of Internet Protocol (IP): IPv4 and a new version called IPv6. IPv6 is an evolutionary upgrade to the Internet Protocol. IPv6 will coexist with the older IPv4 for some time.

What is IPv4 -- Internet Protocol Version 4?

IPv4 (Internet Protocol Version 4) is the fourth revision of the Internet Protocol (IP) used to to identify devices on a network through an addressing system. The Internet Protocol is designed for use in interconnected systems of packet-switched computer communication networks .

IPv4 is the most widely deployed Internet protocol used to connect devices to the Internet. IPv4 uses a 32-bit address scheme allowing for a total of 2^32 addresses (just over 4 billion addresses).  With the growth of the Internet it is expected that the number of unused IPv4 addresses will eventually run out because every device -- including computers, smartphones and game consoles -- that connects to the Internet requires an address.

What is IPv6 -- Internet Protocol Version 6?

IPv6 (Internet Protocol Version 6) is also called IPng (Internet Protocol next generation) and it is the newest version of the Internet Protocol (IP) reviewed in the IETF standards committees to replace the current version of IPv4 (Internet Protocol Version 4).

IPv6 is the successor to Internet Protocol Version 4 (IPv4). It was designed as an evolutionary upgrade to the Internet Protocol and will, in fact, coexist with the older IPv4 for some time. IPv6 is designed to allow the Internet to grow steadily, both in terms of the number of hosts connected and the total amount of data traffic transmitted.

IPv6 is often referred to as the "next generation" Internet standard and has been under development now since the mid-1990s. IPv6 was born out of concern that the demand for IP addresses would exceed the available supply.
While increasing the pool of addresses is one of the most often-talked about benefit of IPv6, there are other important technological changes in IPv6 that will improve the IP protocol:
  • No more NAT (Network Address Translation)
  • Auto-configuration
  • No more private address collisions
  • Better multicast routing
  • Simpler header format
  • Simplified, more efficient routing
  • True quality of service (QoS), also called "flow labeling"
  • Built-in authentication and privacy support
  • Flexible options and extensions

The Difference Between IPv6 and IPv4 IP Addresses

An IP address is binary numbers but can be stored as text for human readers.  For example, a 32-bit numeric address (IPv4) is written in decimal as four numbers separated by periods. Each number can be zero to 255. For example, 1.160.10.240 could be an IP address.

IPv6 addresses are 128-bit IP address written in hexadecimal and separated by colons. An example IPv6 address could be written like this: 3ffe:1900:4545:3:200:f8ff:fe21:67cf (see "What does an IPv6 address look like?")

IPv4 Vs IPv6 (Advantages and Disadvantages)

We can see the rapid growth of internet users in last few years and this increase also create challenges for internet management groups, stake holders and service providers. Day by day infrastructure of internet is expanding and we can even enjoy the service of internet in villages and remote areas. Increased of usage also increase online devices. In start internet protocol addressing (a specific IP addressing for each online entity) was designed on 32 bit and this scheme IP version called IPv4.IPv4 addressing is like 203.128.076.001. decimal is used to make the IPv4 addresses more palatable for humans and a 32-bit address becomes 4 decimal numbers separated by the period (.) character. If we calculate these decimal values and we can get the total number of devices can be participate on this protocol (256x256x256x256) = allows for 4,294,967,296 addresses. It is about 4 billion of addresses and in early days of internet no one can think, 4 billion slot will be full. here we shall discus some disadvantages of IPv4 as we have seen addressing capability problem and after that we shall go through the solution which will replace IPv4 and addressing structure of the new addressing scheme. we shall go through some disadvantages of IPv4 and new features of IPv6.
 
Rapid Growth of the Internet and the Exhaustion of the IPv4 Addressing

IPv4 allows for 4,294,967,296 addresses which is about 4 billion and IP allocation limits the public IP addresses to a few hundred million. Cause of this limitation companies using NAT (Network Address Translator) to map single public IP to multiple private IP addresses.

IPv4 Security at IP Level

When we communicate at public medium we need to encrypt data to maintain security and privacy. After a passage of time we have now security for IPv4 packets. This security knows as internet protocol security or IPSec but this is an optional for IPv4.

Internet Backbone Maintaining Large Routing Tables

In IPv4 network IDs allocation is very critical and currently more than 87000 routes in the routing tables of internet backbone routers today. The routing infrastructure is based on flat and hierarchical routing.

Quality of Service Concern in IPv4

Now a days internet users are not only limited with browsing and searching data. Current users are well aware of text and voice and video chat and video conferences and online video libraries. This kind of communication need real time data transfer for quality of service. Normally for these kind of services we use UDP (User Data-gram Protocol) or TCP (Transmission Control Protocol).IPv4 TOS field has limited functionality and, over time, has been redefined and locally interpreted. Additionally, payload identification that uses a TCP or UDP port is not possible when the IPv4 packet payload is encrypted.

IPv6

As we can see we have some basic problems in practice of IPv4 now we will check some new features of IPv6. here I like to describe the some of basic features of IPv6. Deployment of IPv6 is a big challenge for internet management groups, stake holders and service providers. It is difficult but not impossible. We can see benefits of IPv6 here. Biggest upgrade jump from IPv4 32 bit to IPv6 128 bit.

IPv6 Header Format

New header is designed to minimize header overhead. by moving both nonessential and optional fields to extension headers that are placed after the IPv6 header. IPv6 header is more efficiently processed at intermediate routers and that generates efficiency. IPv6 is 4 time larger than IPv4 and its header size is twice than older version.

IPv6 Large Addressing Space

In IPv6 source and destination addresses is based on 128 bit. 128 bit addressing can produce over 3.4 x 1038 possible combinations. Currently we can say this is enough but who know about future may be it also face same problem like IPv4 after some decades. 128 bit addressing allow us multiple levels of sub-netting and address allocation. So we can say that we have plenty of address for use in future.

Addressing and Routing Infrastructure Efficiency in IPv6

IPv6 designed to create an efficient, hierarchical, and summarize able routing infrastructure that is based on the common occurrence of multiple levels of Internet Service Providers. It reduce the size of routing table of backbone routers. Which is can cause of efficient internet experience.

Security features is now built-in

IPv6 has been design to support IPsec (AH and ESP header support required) also support mobility version Mobile IPv6. IPSec based on two types of extension headers and a protocol to negotiate security settings. The Authentication header (AH) provides data integrity, data authentication, and replay protection for the entire IPv6 packet. It is better form developers who built-in security features in development of IPv6 rather we bolt on later.

Quality of Service (QoS) of IPv6

As we have already seen about the UDP and TCP protocols for streaming and other multimedia services on internet. Cause the usage of these services are increasing day by day IPv6 have a flow level field in its header which make better and special handling for packets from source to destination. Data traffic is identified in the IPv6 header, support for QoS can be achieved even when the packet payload is encrypted with IPSec and ESP.

 

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