W W W . S S B T E C H C O M P U T E R . B L O G S P O T . C O M
Firewall
A firewall is a system designed to prevent unauthorized & uncertain access to or from a private network. You can implement a firewall in either hardware, or software or form are a combination of both. Firewall prevent unauthorized internet users from accessing private network connect to the internet especially intranets. All messages entering or leaving the internet (for example the local network to which you were connected) must pass through the firewall which examines its messages and blocks those that do not meet the specified security criteria. There are many variants of firewalls each has a slightly different application. when looking to install a firewall, it is not a simple answer to give when asked which one to select. Do the need assessments determine why you need a firewall? Take a look below to determine the firewall types that will meet your need after you determine the type of firewall you need the heart set step will the selecting a vendor.
Types of Firewall--
- 1. Free Firewall
- 2. Desktop or Software firewall
- 3. Hardware Firewall
Free firewall
Many software and text firewalls are free many of these firewalls are Linux or BST base and can be quickly set up to protect a small to the medium-sized company quickly also free fire often came in the form of a desktop firewall (sometimes called a personal firewall)
Desktop firewall or Software firewall
Any software installed on an operating system to protect a single computer like the one included with Windows XP is called a desktop or personal firewall this type of firewall is designed to protect a single desktop computer this is a great protection mechanism if the network firewall is compromised. The firewall is optimized to protect applications such as web applications and email servers. Software firewalls have complex filters to is inspect the content of the network traffic to insecure that the type of traffic is properly formatted. This type of firewall is usually behind a hardware firewall.
Hardware firewall
It is a dedicated hardware device with a property operating system or a stripped-down operating system core. This firewall includes network routers with additional firewall capability. Please firewalls are designed to handle a large amount of network traffic. These are often placed on a perimeter of the network to filter the internet noise and only allow predetermined traffic into the network. Sometimes hardware firewall is used in conjunction with the software firewall show the hardware firewall filters out the traffic and the software firewall inspects the network traffic. When hardware firewalls are bombarded with a bogus network traffic update drop the unwanted traffic only letting the right traffic. This not only protects the software firewall but allows the software only had to inspect proper network traffic does the combination of demise the network throughput.
Firewall techniques
- 1. Packet filtering
- 2. Circuit level gateway
- 3. Proxy server
Packet filtering---
This system examines each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to the users, but it is difficult to configure in addition, it is susceptible Pitbull to IP spoofing.
Circuit level gateway --
This process applies a security mechanism when a TCP or UDP connection is established once the connection has been made packets can flow between the hosts without further checking.
Proxy server--
A proxy server is a type of gateway that hides the true network address of computers connected through it. A proxy server that connects to the internet makes the request for the page to be connected to service and receive the data on behalf of computers. The firewall capital built is lie in the fact that proxy can be configured to allow only certain types of traffic.
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