Why Are Firewalls Important?

Businesses and organizations invest a good amount on cybersecurity depending on how crucial their business is; i.e., implementing basic SSL certificates if it is just a personal blogging website and for E-commerce websites, it is recommended to choose strong website security. Firewalls are also one of the security measures that protect a system from hackers and cybercriminals that are active over the Internet hacking and tampering with the functionalities of a system.

Firewalls are specifically configured to prevent unauthorized access to an individual system or a network of computers. They act as a barrier to filter data between the system and the Internet. All messages, whether they are coming from an external source or leaving the system, are passed through the firewall and if they do not pass the specified criteria they are discarded. For example, organizations can limit the access to various websites from their official network thus controlling how the employees use their network. They also work as a filter to block the incoming and outgoing traffic on the network that may be suspicious and unsafe.

Types of firewalls

  • Hardware firewalls
    A simple concept of a hardware firewall is that it sits between your system and the network in a box, not on a computer and needs an Expert IT department to configure and monitor it. They generally perform the packet filtering by analyzing the packets and letting the legitimate ones be received and discarding the suspicious ones.

  • Software firewalls
    These firewalls are installed on individual systems and have the capability to filter the incoming as well as the outgoing traffic on the network. One common drawback is that they need to be updated, administered and installed on each and every computer and be upgraded from time to time.

Let us see how the Firewalls control traffic,

  • Packet Filtering
    The information exchange that takes place between the system and the Internet is divided into small chunks of data packets. These data packets are filtered and if they pass the bill they are accepted, otherwise they're discarded. It protects the routing engine from malicious software or untrusted packets.

  • Proxy service/Application layer firewall
    Proxy servers are the advanced stage of the filtering where they act at the application layer of the firewall. The main concept behind this proxy server setup is that they centralize all the activity at a single server making it possible to perform various other functions apart from just checking for the port numbers and source destination addresses.

  • Stateful inspection
    This kind of firewall is configured in such a way that it distinguishes between legitimate packets for various types of connections. In this type of filtering the entire information of the packet is not analyzed rather only key components are checked with a trusted database source. Packets that match the criteria for a specified connection are only allowed to pass. SPI is also called stateful packet inspection and is widely used for business networks as a security feature. A business network cannot rely on cheap SSL certificates or average firewall security -- they always need high-end protection.

  • Circuit-level gateway firewall
    These firewalls operate at the session layer of the OSI model. They are specifically designed to monitor the TCP handshaking to ensure whether a connection is legitimate or not.

Cyber Security at various levels is essential nowadays as more and more people are connected to the Internet and it is being used for a large number of operations.