What Is Firewall


In computer networking, a firewall is often a crucial network safety device that controls and monitors incoming and outgoing network communications according to predetermined, pre-set security criteria. The firewall must operate at higher levels of security than other applications and processes, such as anti-virus software. It is used to control and restrict Internet traffic as well as restrict access to various file systems and storage devices. A firewall can prevent or limit access to applications and files on a local or remote machine, and can be configured to allow or disallow certain types of traffic, depending on the needs of the user. A firewall often also sets up a barrier between an untrusted remote network and a trusted local network, including the Internet.

Some firewalls are designed for basic packet filtering. Such firewalls can be used in conjunction with other security appliances such as antivirus software or network security suites. For simple packet filtering, there is usually only a single layer of security on the appliance running firewalls. However, more complex firewalls that can perform more realistic traffic filtering can be installed on individual computers or servers.

Simple packet filters can be configured using a standard web browser, or through the use of telnet or Secure Shell (SSH). There are some advanced packet filter firewalls, called application firewall, which can block specific types of Internet traffic, depending on the authorization provided by the administrator. However, in many cases, the simple, firewall-based packet filter will be enough to protect a system. Application firewalls, which run directly against the operating system and frequently scan for suspicious entries, can sometimes be more sensitive to attack and are used in more complex firewalls.

A hardware firewall is not the only option for controlling network traffic. There is also the option of using software firewalls. Software firewalls are available for both home and office computers, and work at the same great levels of security as a hardware firewall. In many cases, software firewall products are sold as part of a network installation package. Examples of software that may be included with a home computer network include firewalls for the home network, the office network, router, and server.

Many people are familiar with packet-based firewalls, which filter packets of data before they are transmitted over a network. Packet-based firewalls are usually provided as a service through a telephone line and are useful for blocking out unwanted or dangerous traffic. Examples of packet filters include ICQ, FreeNets, and other protocols. Real-time packet filtering has become very popular over the past decade or so, as many Internet connections utilize higher bandwidth speeds for file and video sharing applications. However, packet filters are often vulnerable to attack from other wireless devices within the same network. This makes it difficult to configure and install firewalls that protect specific networks from each other.

Another popular example of what is firewall is the network intrusion detection and prevention system. IADP is used in the detection and blocking of malicious network activity. A particular IADP device is installed on each computer in a company’s network that has network access. When an intruder (a hacker) penetrates one of these computers, the IADP will log keystrokes and other information about the illegal activity. This information is then sent to a centralized control station, which is used to block access to the computers that have been compromised, and to monitor all Internet activity.

The use of a firewall extends beyond just preventing unauthorized Internet access. A good firewall will also detect and log any hacking attempts that are made against the company network. If a firewall is correctly implemented and maintained, it can help to prevent a variety of threats, including possible computer viruses, spyware, worms, and Trojans.

Installing a good firewall can improve the overall security of your company’s network. Firewalls can be set up for specific networks or can be used for a general purpose. For example, if you only want to block web surfing for a particular employee, you can configure a company firewall to do this. A general purpose firewall can often be used to protect the whole network from the threat of intruders, while special-purpose firewalls can be used for specific purposes, such as protecting your computers from hackers. Regardless of what type of firewall you use, it is important that you keep your company’s firewall updated, so that it can properly detect and block hackers, rather than allowing them to get through.