What is IP ?

Editor — Sat, 17 Jul 2021 20:05:57 +0000

IP stands for Internet Protocol which is the communications protocol of digital message formats and rules for exchanging messages between computers across a single network or a series of interconnected networks, using the Internet Protocol Suite (often referred to as TCP/IP
Internet Protocol is connectionless and unreliable protocol. It ensures no guarantee of successfully transmission of data.
Messages are exchanged as datagrams, also known as data packets or just packets.
IP consisting of four abstraction layers : link layer (lowest), Internet layer, transport layer and application layer (highest).

What is an Addressing Scheme ?

Editor — Sat, 17 Jul 2021 18:39:00 +0000

An addressing scheme is obviously a requirement for communications in a computer network.
An addressing scheme, packets are forwarded from one place to another.
Each of the three layers, 2, 3, and 4, of the TCP/IP protocol stack model produces a header, as indicated in below diagram.
In this figure, host 1 communicates with host 2 on a network of seven nodes, R1 through R7, and a payload of information encapsulated in a frame by the link layer header, the network layer header, and the transport layer header is carried over a link.
Within any of these three headers, each source or destination is allocated an address as identification for the corresponding protocol layer.
The three types of addresses are summarized as follows.
- Link layer (layer 2) address
- Network layer (layer 3) address
- Transport layer (layer 4) address

A 6-byte (48-bit) field called Media Access Control (MAC) address that is signified by a 6-field hexadecimal number, such as 89-A1-33-2B-C3-84, in which each field as taken as two bytes long.
Every interface has a unique MAC address. Every input or output of a networking device has an interface to its connected link.
Normally, the same MAC address doesn’t share two interfaces then only safe. Both MAC addresses of a source interface and a destination interface contains by link layer header.

A 4-byte (32-bit) field called Internet Protocol (IP) address that is signified by a 4-field dot-separated number, such as 192.2.32.83, in which each field is taken as one byte long.
An IP address can be known worldwide at the network level.
A network layer header contains both IP addresses of a source node and a destination node.

A 2-byte (16-bit) field called port number that is characterized by a 16-bit number, such as 4,892. The port numbers identify the two end hosts’ ports in a communication.
Any host can be running several network applications at a time and thus each application needs to be identified by another host communicating to a targeted application.
For example, source host 1 requires a port number for communication to uniquely identify an application process running on the destination host 2.
A transport layer header contains the port numbers of a source host and a destination host, as seen in the figure. Note that a transport-layer “port” is a logical port and not an actual or a physical one, and it serves as the end-point application identification in a host.