Firewalls and their importance.

The nations without controlled borders cannot ensure the security and safety of their citizens, nor can they prevent piracy and theft. The point is as the popularity increases, insecure environment also progresses and there was a time when even the business tycoon felt, the insecurity in his n/w and incurred losses. Networks without controlled access cannot ensure the security....or privacy of stored data,nor can they establish a good n/w(network) resource from being exploited by hackers.
Hence, I wanna enlighten the needy with the importance of one of the security feature in network/internet i.e FIREWALLS....
When you connect your private n/w to the internet,you are actually connecting your n/w directly to every other n/w attached to the Internet.
There's no inherent central point of security control. Firewalls are used to create security checkpoints at the boundaries of private n/w. By providing the routing functions between the private n/w and the internet,firewalls inspect all communication passing between the two n/w and either pass or drop the communication depending how they match the programmed policy rules.3
Strong firewalls often protect your n/w at all software layers-from data link layer up through the application layer. Firewalls sit on the border of your network--at those gateways that provide access to other n/w.for this reason, firewall are considered as border security.
Firewalls primarily function using three fundamentals methods :-
->Packet Filtering
->Network Address Translation(NAT)
->Proxy Services
There also other two important security services which I would like to mention:
->Encrypted Authentication
->Encrypted Tunnels
to be contd....

Vasanth , when will the next episode of ur firewall serial wil come??

a very good attempt .. try posting few of them

give credits to original writers