The study of the Importance of firewall understands the Firewall fully. A firewall acts as a security guard, controlling access between the internal network and the external network.
Firewall meaning is prevented Intruders accessing data as well as it protects the confidential data which are available in a network.
A single Firewall is adequate for small businesses. Hence, for larger ones, multiple firewalls may be needed.
Geeksforgeeks says it can be compared with a security guard standing at the entrance of a minister’s home. He keeps an eye on everyone and physically checks every person who wishes to enter the house.
How does the firewall work?
1. Access Control
A Firewall has a set of rules that filters all the incoming data as well as outgoing data.
2. Address / Port Translation
NAT initially devised to alleviate the serious shortage of IP addresses. It could be used by system administrators on the internal networks that are globally invalid.
A sound security system ensures that all incoming and outgoing packets are monitored.
The firewall can log on all malicious packets for later analysis.
Importance of Firewall – Personal Work
The main objective of the firewall is to protect your personal computer and small network from malicious access.
Malicious access is generally caused by malware. It is a basic threat to your computer. Malware / Viruses can be transferred to your computer through E-Mail attachments easily. Trojan horse is one such virus affecting your personal computer.
When attacked, this malicious software will get downloaded to your system automatically. So, this injects viruses thereby stealing your confidential data. Some malicious programs can even damage your system.
Hence, Firewall protection to your personal system becomes very much essential. Protecting your system with a Firewall will either allow the traffic that matches a predetermined set of criteria or avoid such type of traffic at all.
Importance of Firewall – Organizations
Large corporations need complex firewalls to protect their large networks. Firewalls can be configured to restrict the access of some websites such as gaming, social networking, etc.
At the same time, Firewalls can be programmed to prevent the staff from sending certain types of E-mail or restrict them from sending confidential data of the organization.
Since there is no boundary for setting configurations, the corporations can change the rule sets in Firewall based on their need.
Upon configuring Firewalls, the employees allow to remotely log into authorized computers. But all the data communications will be encrypted. To manage the different types of Firewall configurations of large organizations, highly qualified and experienced IT Heads are required.
Firewalls can be classified into several types. We will see how does the firewall work.
- Packet Filtering Firewall.
- Circuit level Gateway Firewall
- Stateful Inspection Firewall.
- Application Level Firewalls.
- Software and Hardware Firewall.
We will discuss them one by one:
1. Packet Filtering Firewall
Packet filtering firewall tests each and every packet that passes on the firewall and examines them.
If it matches with the rule defined, it will be allowed to pass. If it doesn’t, it will not be allowed to pass and the particular packet will be dropped.
Packet filtering Firewall works on the Network layer of OSI model.
Thus, it basically creates the checkpoint at the router or Switch.
It will not check the content of the packets. But checks the Port number, IP address, Packet type etc.,
This packet filtering firewall provides less security. Since it doesn’t check the payload, hackers can send malicious data.
Hence, we need a stronger Firewall.
2. Circuit Level Gateway Firewall
This type of Firewall works at the session layer of the OSI model or between the application layer and the TCP/IT protocol stack (shim layer).
It monitors TCP handshaking between the packets to find whether the session is legitimate or not.
It also does not check the content of the packets. So even if the packet contains malicious data or malware, it allows the packet as the handshaking. would have been right.
This is the reason circuit-level gateways are not good enough to protect an organization or a system.
Hence, we need a more robust Firewall.
3. Stateful Inspection Firewall
This type of firewalls combines the features of packet filtering firewall and the TCP handshaking (Circuit-level Gateway).
It provides more protection compared to the above two methods.
Thus, may take more time for transferring legitimate packets as it combines both the architectures.
Hence, we need a higher level firewall.
4. Application level Gateway Firewall (Cloud Firewalls)
Application level gateway firewall implements on the proxy server or via a cloud-based solution.
It filters incoming traffic to the set specifications, i.e., filters only transmitted data.
This firewall first establishes the connection to the source of traffic. It then examines all the incoming packets.
This firewall acts as the circuit level gateway firewall and it checks the contents of the packet. The contents of the packet checks for any malicious data.
After examining the packet content, if it’s approved to transfer, then the proxy sends the packet.
Here again, we may have some significant slowdown because of extra examination of the packets.
5. Software and Hardware Firewall
Software Firewalls need to be installed on individual computers on the network.
All the networks are not compatible with the firewall on every computer or device.
This type of firewall needs installation, updating, maintenance on each and every device. This leads to risk and is time-consuming.
Hardware firewalls are places between the local network of our computers and the Internet.
This firewall checks all the incoming packets coming from the Internet. So, if the packet is legitimate, it allows the packet to transfer. Otherwise, if it contains malware, it drops the packets. Uses of Firewall need to be considered much.
The major drawback of the hardware firewall is the possibility of an insider attack. Insider attacker bypasses all the features of the hardware firewalls.
Hence, Setting up a Hardware Firewall needs IT, experts. If the corporate does not have an excellent IT department, this firewall may not be suitable.
The importance of firewall we have discussed in different ways. Let’s move on to the major tips for using firewall.
Major Tips for using Firewall
1. Keep your Firewall always switched ON.
If there is any necessity such as Installing, troubleshooting etc, you can turn off your firewall. But it is not always advisable. So, better keep the Firewall always in “ON” mode.
2. Lockdown Virtual Private Network (VPN) access.
VPNs cause numerous internal security threats. The access control list needs to be established for limiting down the VPN users.
3. Implement Security Policy.
The intelligent security policy should be established. When the business policy is changed, it should be automatically reconciled with the security policy.
4. Shutdown the unused network services.
Large organizations might have a number of servers. The unused servers can be shutdown.
5. Keep updated version of OS.
Always use the latest version of the Operating system
6. Updates Firewall regularly.
Outdated security software may have loopholes for the attackers. So, firewalls need to be updated on a regular basis.
We have discussed the importance of Firewall and its various types. If only we could follow the major tips given, we can have a robust network security feature of the firewall.