1. Network Elements
● NIC card
● DHCP server
● DNS server
These are kind of telecommunication equipment that provide support and
service to the user.
Example: Router, Switch, Hub, Bridges, NIC card and Gateway etc.
Router is a networking device that
forward packets between networks.
It works at Network Layer (Layer 3).
It is used to connect two or more
It use IP addresses to transfer data
packets between sender and
It manages the traffic load in the
Switch is a networking device used
to connect many devices together
in the network.
It works on data link layer(Layer 2)
It is used in LAN network to connect
two or more nodes in the same or
Switch use MAC address to route
the packet in the network
Switch contain 24/48 ports
Hub is also a networking device
which connects various nodes or
devices in the network.
It is same as that of switch but the
difference is it broadcast the
packets to all nodes which are
connected to it.
It works on Physical Layer (Layer 1).
It contain 4/12 ports.
It cannot store or learn MAC addresses.
Bridge is a networking device which
connect two or more LAN networks
that uses the same protocols (i.e
Ethernet or Token Rings).
It works on Physical or Data link
It recognizes the MAC address.
Bridges has one incoming and
Network Interface Controller/Card
It is also known as Network or LAN
adapter, physical network interface.
NIC cards are the computer’s
hardware components (circuit
board) which is installed to connects
the computer to the computer’s
It provide the computer a dedicated,
full time connection to the network.
Ethernet cable is used to connect
the computer to the network
Gateways is a network point that act
as the entrance point to the another
It controls the traffic between the
It repackage and convert the data
going from one network to the
Example: if we are using internet
connection at home, then gateway
is the internet service provider that
provide access to the entire internet.
Modem is an internetworking device
which is used to transmit data over a
It main function is to modulates and
demodulates the data signals.
It consist of 2 ports. One connected to
ISP and next port is connected to
router.It works on Data link layer(Layer
2). A modem can work without a router (as to connect single pc with internet).
Repeater is a networking device that
receive a signal and retransmit it
Repeaters are installed in the
network to transmit the signals to
Types of repeaters are telephone
repeaters, optical communication
repeaters and radio repeaters.
It works on Physical layer(Layer 1)
Firewall is a network security system
which defines the rules to control
incoming and outgoing network traffic.
It may be a hardware or software
It act as a barrier between trusted
zone (e.g private or corporate network)
and untrusted zone (e.g. the internet)
Software based firewalls are
cyberoam UTM, FireEye, Cisco ASA, Fortinet FortiGate.
Dynamic host configuration protocol
(DHCP) is a client/server protocols
It enables server to automatically
assign an IP address to a computer
and other related information such as
subnet mask and default gateways
from a defined range of numbers
configured for a given network.
DHCP server maintain a pool of an IP
address and leases an address to any
DHCP enabled client when it start up
on the network.
DNS server is a name resolution
protocol for TCP/IP network.
It is a standard for managing the
names of public websites and other
It allow us to type the name of
website in the web browser like
google.com and our computer
automatically find the address on