transison from IPv4 to IPv6

IPng : THE TRANCITION TO IPv6 : 

IPng : THE TRANCITION TO IPv6

Introduction : 

Introduction What is IP? The Internet Protocol (IP) is the method or protocol by which data is sent from one computer to another on the Internet. History In 1978, the Office of the Secretary of Defense (OSD) mandated the use of IPv4 for all “host-to-host” data exchange enabling IPv4 to become the mechanism for the military to create integrated versus stovepiped communications

What we will cover during this presentation : : 

What we will cover during this presentation : IPv4 Address structure The IPv4 address resource problem Network Address translation of private address to global addresses for IPv4 address conservation. Why IPv6? Why not IPv5? IPv6 Specifications (rfc1883) Advantages of ipv6 IPv6 addressing structure (rfc1884) IPv4 to IPv6 transition Need for port number translations in IPv4 to IPv6 NAT(rfc2766)

IPv4 Address Scheme : : 

IPv4 Address Scheme : An IP packet contains several types of information, as illustrated.

Slide 5: 

IPv4 Addressing As with any other network-layer protocol, the IP addressing scheme is integral to the process of routing IP datagrams through an internetwork. Each IP address has specific components and follows a basic format. These IP addresses can be subdivided and used to create addresses for subnetworks, as discussed in more detail later. Each host on a TCP/IP network is assigned a unique 32-bit logical address that is divided into two main parts: the network number and the host number. The network number identifies a network and must be assigned by the Internet Network Information Center (InterNIC) if the network is to be part of the Internet. An Internet Service Provider (ISP) can obtain blocks of network addresses from the InterNIC and can itself assign address space as necessary. The host number identifies a host on a network and is assigned by the local network administrator. The 32-bit IP address is grouped eight bits at a time, separated by dots, and represented in decimal format (known as dotted decimal notation). Each bit in the octet has a binary weight (128, 64, 32, 16, 8, 4, 2, 1). The minimum value for an octet is 0, and the maximum value for an octet is 255.The figure below illustrates the basic format of an IP address.

IPv4 ADDRESSING : 

IPv4 ADDRESSING

IPv4 NAT : 

IPv4 NAT NAT allows an Internet Protocol (IP) network to maintain public IP addresses separately from private IP addresses. NAT is a popular technology for Internet connection sharing. It is also sometimes used in server load balancing applications on corporate networks.

Schema diagram : 

Schema diagram

IPv4 address resource problem : 

IPv4 address resource problem Proliferation of Internet devices: 405M mobile phones sold in 2000 1B+ by 2005 New emerging populations: China, Korea, Japan, India, Russia Solution = IPv6 There are 4,294,967,296 address in IPv4

Why IPv6? Why not IPv5? : 

Why IPv6? Why not IPv5? On any IP header, the first 4 bits are reserved for protocol version. So must be between 0 and 15 4: is already used for IPv4 5: is reserved for the Stream Protocol (STP, RFC 1819 / Internet Stream Protocol Version 2) The next free number was 6. Hence IPv6 was born!

IPv6 Specification (rfc1883) : 

IPv6 Specification (rfc1883) IP version 6 (IPv6) is a new version of the Internet Protocol, designed as a successor to IP version 4 (IPv4) [RFC-791]. The changes from IPv4 to IPv6 fall primarily into the following categories: Expanded Addressing Capabilities IPv6 increases the IP address size from 32 bits to 128 bits, to support more levels of addressing hierarchy, a much greater number of addressable nodes, and simpler auto-configuration of addresses. The scalability of multicast routing is improved by adding a "scope" field to multicast addresses. And a new type of address called an "anycast address" is defined, used to send a packet to any one of a group of nodes.

IPv6 Specification (rfc1883) : 

IPv6 Specification (rfc1883) Header Format Simplification Some IPv4 header fields have been dropped or made optional, to reduce the common-case processing cost of packet handling and to limit the bandwidth cost of the IPv6 header. Improved Support for Extensions and Options Changes in the way IP header options are encoded allows for more efficient forwarding, less stringent limits on the length of options, and greater flexibility for introducing new options in the future. Flow Labeling Capability A new capability is added to enable the labeling of packets belonging to particular traffic "flows" for which the sender requests special handling, such as non-default quality of service or "real-time" service. Authentication and Privacy Capabilities Extensions to support authentication, data integrity, and (optional) data confidentiality are specified for IPv6.

Advantages to IPv6 : 

Advantages to IPv6 Larger address space Reduce end-to-end delay Higher level of security Mobility No fragmentation Network autoconfiguration

IPv6 ADDRESSING : 

IPv6 ADDRESSING IPv6 uses 128 bit addressing mode We can have 340,282,366,920,938,463,463,374,607,431,768,211,456 addresses in scientific notation as about 3.4*10 ^38 addresses That’s about 340 trillion, trillion, trillion addresses

IPv6 ADDRESSING : 

IPv6 ADDRESSING we would split the 128 bits into 16 octets and represent each with a decimal number from 0 to 255. A typical IPv6 address in this notation would appear as follows: 128.91.45.157.220.40.0.0.0.0.252.87.212.200.31.255

128.91.45.157.220.40.0.0.0.0.252.87.212.200.31.255 : 

128.91.45.157.220.40.0.0.0.0.252.87.212.200.31.255

IPv6 Addressing scheme overview : 

IPv6 Addressing scheme overview Unicast Global aggregatable Site local Link local IPv4 compatible Anycast Multicast No more broadcast! There are no broadcast addresses in IPv6, their function being superseded by multicast addresses.

How will the transition take place? : 

How will the transition take place? IPv4 and IPv6 will have to coexist. This won’t happen overnight! How do IPv4 &IPv6 communicate?

Transition Plan (RFC 1752) January 1995 : 

Transition Plan (RFC 1752) January 1995 The IPv6 transition plan is aimed at meeting four basic requirements: Incremental upgrade Incremental deployment Easy addressing Low start-up costs

An algorithm to make this IPv4/IPv6 node : 

An algorithm to make this IPv4/IPv6 node The IPv6/IPv4 node uses standard IPv4 mechanisms or protocols to acquire its own IPv4 address. The node uses this address as its IPv4 address. The node prepends (adds at the beginning) the 96-bit prefix 0:0:0:0:0:0 to the 32-bit IPv4 address that it acquired in step (1).

Conclusion : 

Conclusion Yet as a knowledgeable network professional we need to know about IPv6 issues. Now there is only 8% of IPv4 address are free In near future not more than one & half year IPv4 will be filled We don’t get address shortage in future with IPv6 IPv6 to IPv4 NAT is just an iterim solution, will not work with all protocols.

Slide 22: 

Presented by D.Tharun & G.Srikanth