Monday 21 November 2016

Internet protocal (IP)

Protocol

  • In computing, a protocol or communication protocol is a set of rules in which computers communicate with each other.
  • It also says how to end the communication.

IP

  • IP stands for internet protocol. It is a network layer protocol.
  • IP is a 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).
  • It is a connection less protocol.
  • Each packet that travels through the Internet is treated as an independent unit of data without any relation to any other unit of data.


IP classes

  • IP contains several classes of IP addresses to be used efficiently in various situation as per the requirement of hosts per network.
  • IP have 5 types of classes.


  • All the classes are identified by the first octet of IP Address.

Class A address
  • The first bit of the first octet is always set to 0.
  • So the first octet range from 1-127.


  • Class A addresses only include IP starting from 1.x.x.x to 126.x.x.x only. The IP range 127.x.x.x is reserved for loopback IP addresses.
  • The default subnet mask for class A is 255.0.0.0.
Class B address
  • An IP address which belongs to class B has the first two bits in the first octet set to 10.


  • Class B IP Addresses range from 128.0.x.x to 191.255.x.x.
  • The default subnet mask for class B is 255.255.x.x.
Class C address
  • The first octet of Class C IP address has its first 3 bits set to 110, that is:


  • Class C IP addresses range from 192.0.0.x to 223.255.255.x.
  • The default subnet mask for class C is 255.255.255.x.
Class D address
  • Very first four bits of the first octet in Class D IP addresses are set to 1110, giving a range of:


  • Class D has IP address rage from 224.0.0.0 to 239.255.255.255.
  • Class D is reserved for multicasting.
  • It does not contain any subnet mask.
Class E address
  • Class E addresses are defined as experimental and are reserved for future testing purposes.
  • IP addresses in this class ranges from 240.0.0.0 to 255.255.255.254.
  • Like D classes it also does not have any subnet mask.

Functions

  • The Internet Protocol is responsible for addressing hosts and for routing datagrams (packets) from a source host to a destination host across one or more IP networks.
  • For this purpose, the Internet Protocol defines the format of packets and provides an addressing system that has two functions: Identifying hosts and providing a logical location service.
Datagram construction
  • Messages are exchanged as datagrams, also known as data packets or just packets.
  • For this purpose, IP defines packet structures that encapsulate the data to be delivered.
  • It also defines addressing methods that are used to label the data gram with source and destination information.
  • Each datagram has two components: a header and a payload.
  • The payload is the data that is transported.


IP addressing and routing
  • Routing consists of forwarding IP packets from source to destination machines over a network, based on their IP addresses.


TCP/IP

  • TCP and IP work together to transmit data over the Internet, but at different levels.
  • TCP is the protocol that ensures reliability in a transmission, that which ensures that there is no loss of packets, packets are in the right order, delay is to an acceptable level and no duplication of packets. All this is to ensure that the data received is consistent, in order, complete and smooth.
  • TCP take the responsibility to deliver the data to the destination.


IP version

IPV4
  • IPV4 is a connection less protocol for use on packet-switched networks.
  • It operates on a best effort delivery model, in that it does not guarantee delivery.
  • IPV4 supported my modems, servers, printers, cameras etc.
Advantages
  • Support to all operating system.
  • It is simpler and easy to remember.
  • Require less memory.
Disadvantages
  • It does not identify any security mechanism.
  • Limited to IPV4 address availability.
IPV6
  • IPV6 provides a platform on new internet functionality that will be needed on the immediate future and provide flexibility and growth.
Advantages
  • It has new header format.
  • Large address space.
  • It have built in security.
  • Efficient and hierarchical addressing and routing infrastructure.

No comments: