Using Linux Firewalls

The problem of "network security" has begun to arouse the concern of the majority of the world as applications of the Internet have recently swept across the globe, and based on this problem, a "Firewall" (firewall) has been developed so that it can be used to prevent intruders from outside the Internet. This article will be "Firewall" and "Linux" to do a combination, introduce you to build a Linux firewall.

Linux old friend new friends for a long time did not meet on paper, I hope to take this rare opportunity to use a short article and we share this glad small experience.

Since the national Information Superhighway (NII) has been pushed forward, successive tanet, SeedNet, hinet painstakingly, the internet has become almost a hot topic of the magazine, and "Join the Internet, The use of internet"has also become a way to build corporate image. Amid a flurry of internet turmoil, people are beginning to worry about the so-called "cyber security" problem. Because of the openness of the Internet, it has benefited all members, but also because of his openness, the issue of "cyber security" should be considered. This time we're going to talk about the topic that started with this-"Firewall" (firewall) is a product of this "cyber security" consideration.

We can set up a machine with firewall function between the internal network and the outside network connection, use it to filter the data transmitted between the two networks, and then restrict the network functions that different users can use through the related software settings. The data to be transmitted from the external network to the internal network must be transferred by setting up the firewall machine, and the internal network data will transmit the data to the destination on the external network through this firewall. As a firewall machine, it became a transfer station between the Internet. So when the alien visitor comes, since his footsteps only reached firewall, the worst case was that the "firewall machine had been destroyed!!", but the internal network could have survived and "survived", based on the principle of sacrificing the ego to complete my own, the cost seemed worth it.

While such procedures may seem cumbersome, they can, in some cases, prevent the intrusion of external Internet intruders to secure the intranet. On the other hand, it can restrict the internal network communication to the external network and do another layer of network data flow control. Of course, for this security issue, we have to sacrifice a lot of "convenience", "speed" on the enjoyment, but there will always be a way to make up, these will be the content of our involvement.

The erection pattern of firewall is not unique, it depends entirely on the function of the operating system and the firewall software. The graph above is one of the simplest firewall architectures. After saying some firewall words, we have to do a combination of "Linux" with our protagonist and start to really jump into our focus on how to use Linux to build a firewall".