A firewall is a network security device that monitors incoming and outgoing network traffic and decides whether to allow or block specific traffic based on security rules. Firewalls have been a first line of defense in network security for over 25 years. Firewalls act as a barrier between trusted and untrusted networks and try to block the spread of computer attacks, similar to a physical firewall. There are different types of firewalls including packet filtering, circuit-level gateways, stateful inspection, and application-level gateways. Firewalls analyze incoming traffic based on pre-established rules and filter suspicious sources to prevent attacks by guarding ports where information is exchanged.

1. B I K R A M K U M A R
Firewall

2. • A firewall is a network security
device that monitors incoming and
outgoing network traffic and decides
whether to allow or block specific
traffic based on a defined set of
security rules.
• Firewalls have been a first line of
defense in network security for over
25 years.
What is a Firewall?

3. • In the computing world, the terminology firewall security refers to a network
device which blocks certain kinds of network traffic. Actually, it acts as a barrier
between a trusted and an untrusted network.
• The firewall security wall can be compared to a physical firewall in the sense that
firewall security tries to block the spread of computer attacks.
What is Firewall security?

4. 1.Packet filtering firewall
2.Circuit-level gateway
3.Stateful inspection firewall
4.Application-level gateway (proxy firewall)
5.Next-generation firewall (NGFW)
Types of Firewalls :

5. How does a Firewall work?
• Firewalls carefully analyze incoming traffic based on pre-established rules and filter
traffic coming from unsecured or suspicious sources to prevent attacks. Firewalls guard
traffic at a computer’s entry point, called ports, which is where information is
exchanged with external devices. For example, “Source address 172.18.1.1 is allowed
to reach destination 172.18.2.1 over port 22."
• Think of IP addresses as houses, and port numbers as rooms within the house. Only
trusted people (source addresses) are allowed to enter the house (destination address)
at all—then it’s further filtered so that people within the house are only allowed to
access certain rooms (destination ports), depending on if they're the owner, a child, or
a guest. The owner is allowed to any room (any port), while children and guests are
allowed into a certain set of rooms (specific ports).

6. • Block attacks on your private network forced by other networks.
• Define a funnel and set-aside the non-authorized users.
• Firewall security monitor the network and computer and when questionable activity
befalls, it will automatically generate an alarm.
• Monitor and document services using FTP (File Transfer Protocol), WWW (World
Wide Web), and other protocols.
• Control the use of the Internet. Simply block inappropriate content.
Benefits of Firewall Protection :

7. THANK YOU...