What is firewalls in computer and networking?

What is firewalls in computer and networking?

What is firewall and it's types?

Now a day major challenge of organization is to secure their data. For that purpose they trying to secure data using network security tools. Such as firewall or network firewall.
Many organizations even don't know about what is firewall and how important it is and why it is necessary?

What is firewall?

Firewall is type of cyber security tool  used to filter traffic of the network. It is network security device that monitors outgoing and incoming network trafic. It is also decides whether allow or block specific traffic.
Primary use of firewall is to block unwanted traffic and  to allow legitimate traffic. Firewalls are either hardware, software or cloud based, with each type of firewall having it's own pros and cons.

Types of firewall:-
  1. Packet-filtering firewalls
  2. Circuit-level gateways 
  3. Cloud firewalls 
  4. Hardware firewalls 
  5. Software firewalls 
  6. Next -gen firewalls 
  7. Aplication level gateways 
  8. Stateful inspection firewalls 
Now see how these firewalls are work? And which one is the best for your cybersecurity? 

1). Packet-filtering  firewalls 
     This is the basic and oldest type of firewall architecture, Packet-filtering firewalls creates a check point at a traffic router or switch. This firewall checks all data packets passing through the check point, Inspecting all information like organization and destination ip address, packet type, port number and other important surface level information without opening packet.
If Packet doesn't show such information that these types of packets are blocked by firewall. Good thing in this type of firewall is thay don't have huge impact on system performance and they are relatively simple.

2). Circuit-level gateways
       This is another simple firewall type. This type of firewalls easily and quickly deny and approve traffic without consuming any system resources. Circuit-level gateways works by verifying transmission control protocol (TCP) handshake. This TCP handshake is disignrd to confirm the packet from legitimate .
These firewall do not check packet itself. So if packet hold malware with right TCP handshake, it would pass right through. That's why circuit level gateway not enough to protect your data.

3). Cloud firewalls 
      Cloud firewalls also called as firewall-as-a-service (Faas). In this a cloud solution is used to deliver a firewall. Cloud firewall are many time considered as proxy firewalls, since a cloud server are used in proxy firewall setup.
Main benefit of cloud firewall is that they are very easily scaled with your organization. As you need extend capacity you can add additional capacity to cloud  server to filter large trafic load.

4). Hardware firewalls 
     Hardware firewall is the physical device that acts as a similar to traffic router to intercept data packets and traffic requests before they connect to network. Physical appliance-based firewalls like this excel at perimeter security by making sure malicious traffic from outside the network is intercepted before the company's network endpoints are exposed to risk.
Main weakness of hardware firewall is that it is easy for insider attacks to bypass them. But actual capabilities are this type of firewall are depending on manufacturer.

5). Software firewalls 
      Software firewalls include any firewall that installed local device rather than specific hardware. Most important benefit of software firewalls are highly useful for creating defense in depth by isolating individual network endpoint from one another. It is difficult to maintain individual  software firewall on different devices and it is time consuming also. It is not possible compatibility of all devices are meets. In this case we have to use different types of software firewalls to cover all devices.

6). Next -gen firewalls
      Many of the most recently-released firewall products are being touted as “next-generation” architectures. However, there is not as much consensus on what makes a firewall truly next-gen.

Some common features of next-generation firewall architectures include deep-packet inspection (checking the actual contents of the data packet), TCP handshake checks, and surface-level packet inspection. Next-generation firewalls may include other technologies as well, such as intrusion prevention systems (IPSs) that work to automatically stop attacks against your network.

7). Aplication level gateways (Proxy firewalls )
      Proxy firewalls operate at the appliance layer to filter incoming traffic between your network and therefore the traffic source hence, the name “application-level gateway.” These firewalls are delivered via a cloud-based solution or another proxy device. instead of letting traffic connect directly, the proxy firewall first establishes a connection to the source of the traffic and inspects the incoming data packet.

This check is analogous to the stateful inspection firewall therein it's at both the packet and at the TCP handshake protocol. However, proxy firewalls can also perform deep-layer packet inspections, checking the particular contents of the knowledge packet to verify that it contains no malware.

Once the check is complete, and therefore the packet is approved to attach to the destination, the proxy sends it off. This creates an additional layer of separation between the “client” (the system where the packet originated) and therefore the individual devices on your network obscuring them to make additional anonymity and protection for your network.
If there’s one drawback to proxy firewalls, it’s that they will create significant slowdown due to the additional steps within the data packet transferal process.

8). Stateful inspection firewalls 
 Stateful inspection firewalls are the mixture of both packet inspection technology and TCP handshake verification to extend protection level or security of network. this sort of firewall provides more strain on computing resources. this might hamper transfer of legitimate packets compared to other solutions.