INTERNET PROTOCOL

              Internet Protocol or IP is the primary network protocol used on the Internet, developed in 1970s. On the Internet and many other networks, IP is often used together with the Transport Control Protocol (TCP) and referred to interchangeably as TCP/IP.

    Data on an IP network is organized into packets. EacH IP PACKET includes both a header (that specifies source, destination, and other information about the data) and the message data itself.IP functions at layer 3 of the OSI model. 

                                                 

IP Address: 

       A logical numeric address that is assigned to every single computer, printer, switch, router or any other device that is part of a TCP/IP-based network

Pv4 Addressing Notation

          An IPv4 address consists of four bytes (32 bits). These bytes are also known as octets.

For readability purposes, humans typically work with IP addresses in a notation called dotted decimal. This notation places periods between each of the four numbers (octets) that comprise an IP address. For example, an IP address that computers see as

• 00001010 00000000 00000000 00000001

  is written in dotted decimal as

• 10.0.0.1

         Because each byte contains 8 bits, each octet in an IP address ranges in value from a minimum of 0 to a maximum of 255. Therefore, the full range of IP addresses is from0.0.0.0 through 255.255.255.255 

. This represents a total of 4,294,967,296 possible IP addresses.

IPv6 Addressing Notation

      IP addresses change significantly with IPv6. IPv6 addresses are 16 bytes (128 bits) long rather than four bytes (32 bits). This larger size means that IPv6 supports more than

• 300,000,000,000,000,000,000,000,000,000,000,000,000

possible addresses! As an increasing number of cell phones and other consumer electronics expand their networking capability and require their own addresses, the smaller IPv4 address space will eventually run out and IPv6 become mandatory.

IPv6 addresses are generally written in the following form:

• hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh:hhhh

In this full notation, pairs of IPv6 bytes are separated by a colon and each byte in turns is represented as a pair of hexadecimal numbers, like in the following example:

• E3D7:0000:0000:0000:51F4:9BC8:C0A8:6420

      As shown above, IPv6 addresses commonly contain many bytes with a zero value.Shorthand notation in IPv6 removes these values from the text representation (though the bytes are still present in the actual network address) as follows:

• E3D7::51F4:9BC8:C0A8:6420

              Finally, many IPv6 addresses are extensions of IPv4 addresses. In these cases, the rightmost four bytes of an IPv6 address (the rightmost two byte pairs) may be rewritten in the IPv4 notation. Converting the above example to mixed notation yields

• E3D7::51F4:9BC8:192.168.100.32