In the initial years of 1980 when computers were in use people were neither aware of, nor expecting computer hackers. When the first large-scale Morris worm attack took place, people realised the need for a protective device.
This protective device came in the form of firewalls, in the later half of 1980s. A physical firewall keeps fire from spreading. Firewall in computers works similarly. It prevents the spread of destructive forces.
What is a Firewall?
It is an Information Technology (IT) hardware or software security device. This device filters information coming to the computer system through the internet. If any incoming information from the network is prevented by the firewall, the computer user cannot access it. In simple words, computer firewall filters bad data and allows access to good data.
The Different Kinds of Firewall
Network Layer Firewalls
These are also known as packet filters. This firewall works at a relatively low level by allowing only those packets that match the rules to pass through. These rules are defined by the firewall administrator. An alternative variant of this application is allowing the entry of all packets that do not match the deny rules. However, inflexible firewalls operate on built in rules.
Application Layer Firewall
In a network all the computers pass through the proxy server to connect to the internet. The proxy server runs the firewall device.
But sometimes, intruders gain access to a public server. They use this server as a proxy for their own purposes and successfully access a network of computers through the firewall.
Personal Firewall
It combines the aspects of both the network filters described above. But, unlike the other two, it only protects the particular computer system, it is installed on.
This is a software programme that runs on single computers. This device either allows or denies access to information coming from other computers. It provides some amount of intrusion detection by blocking connectivity if intrusion is suspected.
How does It Work?
Basically, firewalls monitor the traffic in computer networks. Home computers and internal network computers are zones of high trust; and, the internet is a no-trust zone. Once the firewall is enabled the inflow and outflow of data between these trust zones is monitored.
A computer user accessing the internet keeps his files potentially exposed. A hacker who gains control can spread malicious codes to obtain personal information of the user like the credit card number and bank account details. Firewalls deny entry to such malicious codes.
Does the Role of Firewalls End by Preventing Access to Anything Unwanted?
Firewalls do not just prevent unwanted data reaching the personal computers. Their role extends beyond this. Firewalls are also used to enforce more complicated security policies as determined by the firewall administrator.
• All the network traffic passes through a firewall. The firewall records the traffic between the external and internal networks.
• Firewall can separate one section of the network from the other. This separation or denial of access is for protecting sensitive data.
• Only certain systems within the firewall are granted permission to transfer and receive files through the internet.
Consequences of not Having a Firewall
Many people do not feel the need to use the firewall protection. They feel that the antivirus software in their system is effective enough. Antivirus software protects the computer against viruses while firewall offers protection against direct hackers.
Once Infected, can Your PC be Saved from Infection?
Computers can get infected in the absence of a firewall. First, the user has to identify how the PC was infected. Most probably, the infection might have spread through an email attachment from an unknown source.
Signs of an Infected PC
• Advertisements appear constantly
• The browser leads to unwanted sites
• The PC unexplainably slows down
• Fails to connect to the internet properly
If these are the symptoms:
• First, a backup must be created for all the important files saved in the computer.
• Next, an antivirus software program must be downloaded. The virus could have attached to one of the program files. The files should be cleaned using the antivirus software and reinstalled.
Antivirus software cannot offer protection against all threats. Once a PC is infected cleaning it up is a very difficult task. A firewall effectively protects computers. Different types of firewalls are available. Computer users can install the best-suited one. Prevention is certainly better than cure, but if the worst happens there are several Data Recovery services available that can save the day.
This protective device came in the form of firewalls, in the later half of 1980s. A physical firewall keeps fire from spreading. Firewall in computers works similarly. It prevents the spread of destructive forces.
What is a Firewall?
It is an Information Technology (IT) hardware or software security device. This device filters information coming to the computer system through the internet. If any incoming information from the network is prevented by the firewall, the computer user cannot access it. In simple words, computer firewall filters bad data and allows access to good data.
The Different Kinds of Firewall
Network Layer Firewalls
These are also known as packet filters. This firewall works at a relatively low level by allowing only those packets that match the rules to pass through. These rules are defined by the firewall administrator. An alternative variant of this application is allowing the entry of all packets that do not match the deny rules. However, inflexible firewalls operate on built in rules.
Application Layer Firewall
In a network all the computers pass through the proxy server to connect to the internet. The proxy server runs the firewall device.
But sometimes, intruders gain access to a public server. They use this server as a proxy for their own purposes and successfully access a network of computers through the firewall.
Personal Firewall
It combines the aspects of both the network filters described above. But, unlike the other two, it only protects the particular computer system, it is installed on.
This is a software programme that runs on single computers. This device either allows or denies access to information coming from other computers. It provides some amount of intrusion detection by blocking connectivity if intrusion is suspected.
How does It Work?
Basically, firewalls monitor the traffic in computer networks. Home computers and internal network computers are zones of high trust; and, the internet is a no-trust zone. Once the firewall is enabled the inflow and outflow of data between these trust zones is monitored.
A computer user accessing the internet keeps his files potentially exposed. A hacker who gains control can spread malicious codes to obtain personal information of the user like the credit card number and bank account details. Firewalls deny entry to such malicious codes.
Does the Role of Firewalls End by Preventing Access to Anything Unwanted?
Firewalls do not just prevent unwanted data reaching the personal computers. Their role extends beyond this. Firewalls are also used to enforce more complicated security policies as determined by the firewall administrator.
• All the network traffic passes through a firewall. The firewall records the traffic between the external and internal networks.
• Firewall can separate one section of the network from the other. This separation or denial of access is for protecting sensitive data.
• Only certain systems within the firewall are granted permission to transfer and receive files through the internet.
Consequences of not Having a Firewall
Many people do not feel the need to use the firewall protection. They feel that the antivirus software in their system is effective enough. Antivirus software protects the computer against viruses while firewall offers protection against direct hackers.
Once Infected, can Your PC be Saved from Infection?
Computers can get infected in the absence of a firewall. First, the user has to identify how the PC was infected. Most probably, the infection might have spread through an email attachment from an unknown source.
Signs of an Infected PC
• Advertisements appear constantly
• The browser leads to unwanted sites
• The PC unexplainably slows down
• Fails to connect to the internet properly
If these are the symptoms:
• First, a backup must be created for all the important files saved in the computer.
• Next, an antivirus software program must be downloaded. The virus could have attached to one of the program files. The files should be cleaned using the antivirus software and reinstalled.
Antivirus software cannot offer protection against all threats. Once a PC is infected cleaning it up is a very difficult task. A firewall effectively protects computers. Different types of firewalls are available. Computer users can install the best-suited one. Prevention is certainly better than cure, but if the worst happens there are several Data Recovery services available that can save the day.