IP means INTERNET PROTOCOL. Here internet
means network of networks & protocol means rules
and regulations used by user while using internet.
The IP is used for communicating data across a
packet switched internetwork.
In May,1974,the Institute of Electrical and
Electronics Engineers (IEEE) published a
paper titled “A Protocol for packet network
The proposal had no affiliation with or
support by any international standards body,
and appears to have gained no traction even
Data from an upper layer protocol is
encapsulated inside one or more packets.
No circuit setup is required for this thus IP is
a connectionless protocol.
This is unlike Public Switched Telephone
Networks that require the setup of a circuit
before a phone call may go through.
Services provided by IP
IP can be used over a Hetrogeneous network
(i.e., ethernet, ATM, Wi-Fi).
Each data link layer can have its own method
of addressing, with a corresponding need of
resolve IP address to data link address. This
address resolution is handled by the Address
Resolution Protocol (ARP).
IP provides an unreliable service. This means that
the network makes no guarantees about the packet
and none, some, or all of the following may apply;
1. Data corruption
2. Out of order delivery
3. Lost or dropped packages
In terms of reliability the only thing IP does is
ensure the IP packet’s header is error-free.
IP addressing and routing
Perhaps the most complex aspects of IP are
IP addressing and routing. Addressing refers
to how end hosts become assinged IP
addresses and how subnetworks of IP host
addresses are divided and grouped together.
Data always try to travel through shortest
path, this process is called Routing. This is
done by Routers.
DNS (Domain Name Server)
The Domain Name System consists of a
hierarchical set of DNS servers. Each
domain or subdomain has one or more
authoritative DNS servers that publish
information about that domain and the name
servers of any domains "beneath" it. The
hierarchy of authoritative DNS servers
matches the hierarchy of domains. At the top
of the hierarchy stand the root.