Learn about FireWall

The Internet allows us to access anywhere in the world through a number of services.Sitting in front of your computer you can know information globally, but that's why your computer system can be compromised at any time without your knowledge.Therefore, protecting the system is an issue we deserve.The concept of FireWall was introduced to solve this problem.

What is FireWall?

The term FireWall comes from a construction design technique to prevent and limit fires.In Information Network Technology, FireWall is a technology that is integrated into the network to combat unauthorized access to protect internal information sources as well as limit access to certain systems. Other unwanted news.

Internet FireWall is a set of devices (including hardware and software) between an organization's network, a company, or a country (Intranet) and the Internet:

(INTRANET - FIREWALL - INTERNET)

In some cases, the firewall can be set up in the same local network and isolate secure domains.For example, the following model shows a local network using a Firewall to separate the machine room and the network system downstairs.

Function

FireWall determines which services from within are allowed to be accessed from outside, who from outside are allowed to access internal services, and which external services are allowed to be accessed by people inside.

The structure of FireWall

FireWall includes:

One or more server systems connect to routers (routers) or have router functions.

Security management software runs on the server system.Usually authentication systems (Authentication), authorization (Authorization) and accounting (Accounting).

FireWall components

A FireWall includes one or more of the following components:

+ Packet filter (packet- filtering router).

+ Application port (Application-level gateway or proxy server).

+ Circuite level gateway.

What does FireWall protect?

FireWall's basic mission is to protect the following issues:

+ Data: Information should be protected due to the following requirements:

- Security.

- Integrity.

- Timeliness.

+ System resources.

+ The reputation of the company that owns the information to be protected.

FireWall protects against what?

FireWall protects against external attacks.

+ Direct attack:

The first way is to use the direct password detection method.Through the password detection program with some user information such as date of birth, age, address, etc. and associated with user-created library, the attacker can detect the password of friend.In some cases the likelihood of success can be up to 30%.For example, the password detection program running on Unix is ​​called Crack.

The second way is to use the bugs of the application programs and the operating system itself that has been used since the first attacks and still be able to gain access (obtain the rights of the system administrator).

+ Eavesdropping: It is possible to know the name, password, and pass information through the network through programs that allow to put the network interface card (NIC) into the mode of receiving all information transmitted over the network.

+ Fake IP address.

+ Disable system functions (deny service).This is a type of attack to paralyze the entire system so that it does not perform the functions it was designed for.This type of attack cannot be prevented because attack media is also the means to work and access information on the network.

+ System administrator error.

+ The human factor with subjective personality and lack of understanding of the importance of system security makes it easy to reveal important information to hackers.

Today, the level of hackers is getting better, while network systems are still slow to handle their vulnerabilities.This requires network administrators to have a good knowledge of network security to keep the information of the system safe.For individual users, they cannot know all the tricks to build themselves a firewall, but should also understand the importance of securing information for each individual, thereby finding out for themselves. Some ways to prevent simple attacks by hackers.The problem is consciousness, when already conscious to prevent, the safety ability will be higher.