Home > Firewall

Firewall acts as a hardware device in computing environment. It also acts as software which provides protection to the computer system or a network from unauthorized access. The function of a firewall in a network is basically to prevent some sort of communications that are unauthorized by the security policy of an organization. In analogy firewalls can be compared to the functioning of boundary firewalls in building or architectural construction.

The basic task of a firewall is to control the traffic which is usually between different zones of trust. Typically these zones of trust include the internet. The zones may be classified as a zone with no trust and an internal network - a zone with high trust. Finally the ultimate goal of the firewall is to provide a controlled connectivity between the zones residing over different trust levels. This is achieved through the enforcement of a security policy. Also a connectivity model based on the principle least privilege can be a basis.

The installation and configuration of the firewall is an important task and also a difficult thing sometimes to be performed. The demand is based on the proper installation and configuration of the firewall. An efficient skill set is required in this case. The person who is configuring the firewall should be capable of administrating a network.

He must be well averse with the complications involved within a network. A proper understanding of the different protocols is necessary as well as the issues involved in computer security and the tools available. The other name given for a firewall is BPD. BPD stands for Border Protection Device. In the context of BSD, the firewall is usually referred to as a packet filter. There are different types of packet filters used in deploying the security in a network.

They are discussed below. The classification of the firewalls is basically done on the following criteria. The first is whether communication is done between a single node and network; or in between two or more networks. The second criterion is whether communication is being intercepted at the network layer. It may also be intercepted at the application layer. The last criterion is whether the state or communication is being tracked at the firewall or not.

The classification on the basis of scope of filtered communication is Personal firewalls and DMZ; where DMZ stands for demilitarized zones. Along the reference of the layers where traffic can be intercepted, the firewalls are classified as in two main categories.

They are the network layer firewalls and the other is application layer firewalls. Finally depending upon the firewalls track packet states, they can be classified as two additional categories stateful firewalls and stateless firewalls. A proxy device can also be implemented as a firewall. The firewall may be running either on dedicated hardware or over software depending upon a general purpose machine.

The response may be related input packets for example connection requests. Firewalls are often required to do NAT - Network Address Translation. Here the host protects a firewall that is commonly as private address space.

More Information
General Information
Hardware
Privacy
Network Forensic Tool
File System
Data Security
Data Analysis
Data Encryption
Data Remanance
Defense Establishment
Networking
Internet Forensic
Data Security
Crime Investigation
Services
Incident Response Systems
Physical Damage
Cyber Crime
Privacy
Impact
Log File Recovery
Advance Partition Recovery
Intrusion Detection System
Data Encryption
Ethics

Related Information
Data Recovery Tools
SCSI RAID
DLT Tape Drives
Business Performance
Software Industry