Comments
Firewall is device which is used for seccuritty in the network
It maay be on software or hardware bases
PIX
ISA
Netscreen
Posted by mrleo99098
Fire wall is used to secure our network on which we make policies as well as we must configure it properly then it prevent our system.
Posted by HamidAliKhan
firewall is basically a secure machine sits between private and public networks & for further explanation see the link below
http://www.faqs.org/docs/linux_network/x-087-2-firewall.introduction.html
Posted by Hash007
A firewall is basically a wall that prevent unathurised access.
Posted by waqqas1
I pulled from the below website on the best answer
http://www.webopedia.com/TERM/f/firewall.html
A system designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.
There are several types of firewall techniques:
Packet filter: Looks at 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 users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.
Application gateway: Applies security mechanisms to specific applications, such as FTP and Telnet servers. This is very effective, but can impose a performance degradation.
Circuit-level gateway: Applies security mechanisms 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: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.
Posted by laya
-