IP which is known as Internet Protocol. It is a very common word in todays life. IP is a very strong column which which represent the Internet.

In 1991, the IETF (The Internet Engineering Task Force ) realize that the latest version of IP, called Ipv4, had outlived its design. They think that, the modern version of IP can Ipng that means Internet Protocol Next Generation or Ipv6 that means Internet Protocol version 6, was the result of a long and troubled process which came to a head in 1994, when the IETF gave a clear direction for Ipv6. This new model of IPv6 is designed to solve the problems of Ipv4.

Limitations of Ipv4

Now in modern age intrnet users IPv4, which is now almost twenty years old. IPv4 was useful but in spite of that it have some problems to beginning. Main problem is that, there is a developing insufficient of IPv4 addresses, which are required by all new machines added to the Internet.

The fix address range forces the organizations to utilize Network Address Translation (NAT) firewalls to map multiple private addresses to a single public IP address. NATs does not support standards-based network-layer security and also makes complexed barriers to VoIP, and other services.

The router table becoming bigger. A totally separate router table entry is required for each network resulting in a large number of router table entries.

Security was also one big problem for IPv4. Although there are many ways of encrypting IPv4 traffic, such as using the IPSec protocol, but unluckily all of the IPv4 encryption methods are proprietary and no real standard encryption methods exist.

Features of Ipv6

The following are the features of the IPv6 protocol:

New header format :

The IPv6 header has a new format that is conceptualize to minimize header overhead. This is succeed by moving both unessential fields and option fields to extension headers that are placed after the IPv6 header. The streamlined IPv6 header provides more efficient processing at intermediate routers.

The IPv6 protocol is not backward matched with the IPv4 protocol. A host or router must utilize an implementation of both IPv4 and IPv6 in order to address and process both header formats. The new IPv6 header is only twice as big as the IPv4 header, even though IPv6 addresses are four times as big as IPv4 addresses.

Large address space :

IPv6 has 128-bit (16-byte) source and destination addresses. Although 128 bits can give over 3.4×1038 possible combinations, the big address space of IPv6 has been designed to supply for multiple levels of subnetting and address allocation from the Internet backbone to the individual subnets within an organization.

Although only a small percentage of possible addresses are now assigned for utilize by hosts, there are plenty of addresses available for future utilize . With a much bigger number of available addresses, address-conservation techniques, such as the deployment of NATs, are no longer necessary.

Efficient and hierarchical addressing and routing infrastructure :

IPv6 global addresses apply on the IPv6 portion of the Internet are designed to produce an effective, hierarchical, and resumerable routing infrastructure that addresses the usual occurrence of multiple levels of Internet service providers. On the IPv6 Internet, backbone routers have very smaller routing tables.

Stateless and stateful address configuration :

To simplify host configuration, IPv6 supports both stateful address configuration, such as address configuration in the presence of a DHCP server, and stateless address configuration (address configuration in the absence of a DHCP server). With stateless address configuration, hosts on a link automatically configure themselves with IPv6 addresses for the link (link-local addresses) and with addresses that are derived from prefixes advertised by local routers. Even in the absence of a router, hosts on the same link can automatically configure themselves with link-local addresses and communicate without manual configuration.

Built-in security :

Play for IPSec is an IPv6 protocol suite need. This need supplies a standards-based solution for network security wants and promotes interoperability between different IPv6 implementations.

Better support for quality of service (QoS) :

New fields in the IPv6 header define how traffic is handled and identified. Traffic identification, by using a Flow Label field in the IPv6 header, allows routers to identify and provide special handling for packets that belong to a flow. A flow is a series of packets between a source and destination. Because the traffic is identified in the IPv6 header, support for QoS can be easily achieved even when the packet payload is encrypted with IPSec.

New protocol for neighboring node interaction :

The Neighbor Discovery protocol for IPv6 is a series of Internet Control Message Protocol for IPv6 (ICMPv6) messages that manage the interaction of neighboring nodes (that is, nodes on the same link). Neighbor Discovery replaces Address Resolution Protocol (ARP), ICMPv4 Router Discovery, and ICMPv4 Redirect messages with efficient multicast and unicast messages and provides additional functionality.

Extensibility :

IPv6 can be extended for new features by adding extension headers after the IPv6 header. Unlike the IPv4 header, which can only support 40 bytes of options, the size of IPv6 extension headers is only constrained by the size of the IPv6 packet.

Difference Between IPv4 and IPv6

IPv4

Source and destination addresses are 32 bits (4 bytes) in length.

IPSec support is optional.

IPv4 header does not identify packet flow for QoS handling by routers.

Both routers and the sending host fragment packets.

Header includes a checksum.

Header includes options.

Address Resolution Protocol (ARP) uses broadcast ARP Request frames to resolve an IP address to a link-layer address.

Internet Group Management Protocol (IGMP) manages membership in local subnet groups.

ICMP Router Discovery is used to determine the IPv4 address of the best default gateway, and it is optional.

Broadcast addresses are used to send traffic to all nodes on a subnet.

Must be configured either manually or through DHCP.

Uses host address (A) resource records in Domain Name System (DNS) to map host names to IPv4 addresses.

Uses pointer (PTR) resource records in the IN-ADDR.ARPA DNS domain to map IPv4 addresses to host names.Must support a 576-byte packet size (possibly fragmented).

Ipv6

Source and destination

addresses are 128 bits (16 bytes) in length.

IPSec support is required.

IPv6 header contains Flow Label field, which identifies packet flow for QoS handling by router.

Only the sending host fragments packets; routers do not.

Header does not include a checksum.

All optional data is moved to IPv6 extension headers.

Multicast Neighbor Solicitation messages resolve IP addresses to link-layer addresses.

Multicast Listener Discovery (MLD) messages manage membership in local subnet groups.

ICMPv6 Router Solicitation and Router Advertisement messages are used to determine the IP address of the best default gateway, and they are required.

IPv6 uses a link-local scope all-nodes multicast address.

Does not require manual configuration or DHCP.

Uses host address (AAAA) resource records in DNS to map host names to IPv6 addresses.

Uses pointer (PTR) resource records in the IP6.ARPA DNS domain to map IPv6 addresses to host names.

Must support a 1280-byte packet size (without fragmentation).