Internet Protocol Versions ---
What happened to IPV1, IPV2, IPV2.5, IPV3, IPV3.1??
Internet Protocol Introduction --
- An IP address is an identifier for a computer or device on a TCP/IP network.
- Protocol (Rules) is a method by which data/Info is sent from one computer to another on the Internet/Network.
Note:- If the PC(Node) is connected to a network as well as the internet ,then the PC will have an Internal (private) IP Address which makes its location on the local network, and on external (Public)IP Address which is the IP address of your internet connection .
History of IP Version --
Earlier the design for TCP was struggling to solve two problems at the same time: how do we establish end to end connectivity/package data, and how do we send that data from one location to another?
TCP version 1 was designed in 1973, TCP version 2 was documented in March
1977. In August 1977, Jon Postel (American computer scientist) realized they were going the wrong direction with the protocols. Specifically they were trying to use TCP to do two things: serve as a host level end to end protocol, and to serve as a routing protocol. These two things should be provided in a different layeres. Then they decided that a new distinct internetwork protocol (IP) is needed .from here TCP and IP works on different platforms.
TCP(TCP Protocol number 6) be used strictly as a host level end to end protocol on layer 4 of the OSI (Open system Interconnection) Model and layer 3 of the TCP/IP (Transmission Control Protocol)Model .
IP (Internet Protocol) be used as a Routing Protocol at layer 3 of OSI Model and Layer 2 of TCP/IP Model.
Variable length addresses were removed, leaving fixed 4-byte(32 bits and 4 Octets) addresses
First TCP and IP split happened , then VLSM removed and size got fixed of 4 Bytes .
IP Versions –
Version numbers: There are 1,2, 2.5, 3, 3.1 and 4
2.5 was a "implementation split", in which the single header remained same, but the code was split into two TCP and IP . Version 3 was the first version that had the headers fully split (and included "protocol numbers" to identify which transport protocol was being used) but it included variable-length addresses TCP 3 was a paper specification driven by the experience gained from running TCP 2.5.
Version 3.1 had the variable-length addresses removed, and Version 4 was proper cleanup of 3.1 and decided it will announce on Internet to use publically. 18-19 September 1978 meeting notes list the schedule for TCP "Version 4 Ready for testing".
Stability was added in the (IPV4) fourth revision of Internet protocol that is how we got to IPv4.
Version 1, Version 2 and Version 3 they were the experimental /test versions
of implementation and improved as the internet started to grow. They did not announce for public use because they were in initial growing stage.
IPv5 is Stream Protocol, It was a failed attempt to expand and solve some of IPv4's problems that's why it also did not announce publically.
IP Headers –
Before Internet Protocol (IP) Version 3 Headers were not split. In Version 3 they Split into different section/fields.
An IP header is a prefix to an IP packet that contains information about the IP version, length of the packet, source and destination IP addresses, etc. It consists of the following fields.
IP Version Numbers –
|5||ST(Stream Protocol)||ST Datagram Mode||[RFC1819][Jim_Forgie]|
|6||IPV6||Internet Protocol version 6||[RFC8200]|
|7||TP/IX||TP/IX: The Next Internet||[RFC6814]|
|8||PIP||The P Internet Protocol||[RFC1621]|