What is Firewall
A firewall can be software/hardware that is developed to protect from hackers/unwanted access from a private network (WAN) by filtering the information that comes in from the internet.
A firewall prevents unauthorized traffic
and allows access to wanted traffic. The main purpose of the firewall is to provide a barrier between a private network (LAN) and
the public internet (WAN). Because
of the Wide Area Network
(WAM) internet, there are always going to be hackers and
malicious traffic that may try to penetrate a private network to cause harm.
Basically, the firewall is developed
to prevent unauthorized access from WIDE AREA NETWORK (WAN). A firewall is very important
for a large-scale organization, where they
have a large number of computers and servers.
As most of organizations have their important and sensitive data on
their local servers. They do not want to share these sensitive data
by any means. That's
why they need a firewall to protect them.
In today's high-tech world, for every computer/device related to the internet
(WAN), a firewall is necessary for every home, business and especially an organization
to keep their network safe from hackers. A firewall filters the
incoming network data (traffic)
and determines by its filter rules if it can
enter a network, these filters are also known as an access control list. These rules can change
and are determined by the network administrator. The network administrator defines the rules for not only what can enter a
network but also what can leave a network.
These rules either allow or deny
permission in the firewall
access control list. Firewalls don't just make rules based on IP addresses, but they can
also make rules based on ports, domain names, protocols, programs, and keywords.
There are
different types of firewalls.
Host Based Firewall:
One type is called a host-based firewall, this
is a software-based firewall. This kind of firewall is installed on a computer and protects that computer only and nothing else.
For example, all versions of the Windows Operation system from Microsoft come pre-packaged host-baseball firewall. The 3rd
party host-based firewalls can also be availed and installed on a computer Zone Alarm etc.
Now days Antivirus programs will have a built-in
host-based firewall.
Network Base Firewall:
Another type of firewall is called a
network-based firewall. A network-based
firewall includes hardware and software, it implements at the network layer.
It is placed between a Local Area Network (LAN) and the Wide
Area Network (WAN) public internet.
A network-based
firewall protects the whole network, and it does this through firewall rules that are
applied to the entire network so that any harmful activity can be stopped
before it reaches the computers. Network-based
firewalls can be a stand-alone product, which is mainly used
by large organizations.
