Page 131 - Web Applications (803) Class 11
P. 131
1.9 IDENTIFICATION OF COMPUTERS AND USERS OVER A NETWORK
After a network has been established, the nodes can communicate with one another. However, the nodes must be
uniquely recognised to communicate properly. If node X sends information to node Y on a network, both nodes X and
Y must be uniquely identified on the network. Let’s have a look at how this is accomplished.
MAC Address
The manufacturer assigns a universally unique address to each NIC. The MAC (Media Access Control) address of the
card is this address. It means that the MAC address of a machine’s NIC can be used to uniquely identify it. A NIC’s MAC
address is static and does not change.
MAC addresses are hexadecimal (48-bit) integers with 12 digits. MAC addresses are commonly written in one of two
formats, according to convention:
MM:MM:MM:SS:SS:SS MM-MM-MM-SS-SS-SS
A MAC address’s first half (MM:MM: MM) contains the adapter manufacturer’s ID number. The serial number assigned
to the adapter (NIC) by its manufacturer is represented by the second half (SS:SS: SS) of a MAC address.
For instance, consider the MAC address 00:A0:C9: 14:C8:35. The manufacturer is Intel Corporation, as indicated by the
prefix 00:A0:C9. The last three numbers 14:C9:34 are assigned to NIC by the manufacturer (Intel in this case).
IP Address
Every machine on a network has its own unique identifier, known as an IP Address. An IP address consists of four bytes
(32 bits), each of which can be any integer between 0 and 255. The following is an example of a typical IP address:
192.077.134.72
IP addresses are usually written in decimal format as a “dotted decimal number” like the one above to make them
easier to remember. On a network, a machine’s IP address, not its NIC’s MAC address, is used to identify it. The user
can update a node’s IP address settings.
You might be wondering what the difference is between an IP address and a MAC address. Let’s have a look:
Mac Address IP Address
It is a hexadecimal address of six bytes. This address can be either eight or six bytes long.
A device's MAC address is provided by the manufacturer of the The IP address of a device is provided by an ISO (Internet
NIC card. Service Provider).
A MAC address is mostly used to verify a device's/physical The logical address of a computer is defined by the IP address.
computer's address.
When a machine is moved from one network to another, its When a machine is moved from one network to another, its IP
MAC address remains the same. address gets changed.
Wing R to Wing P 450 m
Notes
There are two versions of IP addresses that are currently existing on the global Internet—IP version 4 (IPv4) and
IP version 6 (IPv6). IPv4 is 32 bits long whereas IPv6 is 128 bits long. Both versions can coexist on a network.
Domain Name
As a result, we may communicate with a computer over the internet by utilising its IP address. However, remembering
the IP addresses of all the machines with whom one might need to communicate is almost difficult. As a result, a system
Basics of Networking and Web Architecture 129

