Shulou(Shulou.com)06/02 Report--

This article mainly explains "what the firewall can be divided into according to the way the firewall handles the data". Interested friends may wish to take a look. The method introduced in this paper is simple, fast and practical. Next let the editor to take you to learn "according to the firewall data processing method can be divided into what firewall" bar!

According to the data processing method of the firewall, the firewall can be divided into packet filtering firewall and proxy firewall; packet filtering product is the primary product of firewall, and its technical basis is the subpacket transmission technology in the network; proxy firewall can also be called proxy server, its security is higher than packet filtering products, and has begun to develop to the application layer.

Operating environment of this article: Windows7 system, DELL G3 computer

According to the way the firewall handles data, what can be divided into firewalls?

Although the development of firewall has gone through several generations, according to the processing method of internal and external data, it can be divided into two systems: packet filtering firewall and proxy firewall (application layer gateway firewall).

Packet filtering product is the primary product of firewall, and its technical basis is the subpacket transmission technology in the network. The data on the network is transmitted in "packets". The data is divided into packets of a certain size, and each packet contains some specific information, such as the source address, destination address, TCP/UDP source port and destination port of the data. The firewall reads the address information in the packets to determine whether these "packets" come from trusted security sites. Once packets from dangerous sites are found, the firewall will shut the data out. The system administrator can also make judgment rules flexibly according to the actual situation.

The advantage of packet filtering technology is simple and practical, low cost, in the case of relatively simple application environment, it can ensure the security of the system to a certain extent at a small cost.

But the defect of packet filtering technology is also obvious. Packet filtering technology is a kind of security technology based entirely on the network layer, which can only be judged by the network information such as the source, target and port of the data packet, and can not identify the malicious intrusion based on the application layer, such as the malicious Java Mini Program and the virus attached to the e-mail. It is easy for experienced hackers to forge IP addresses and fool packet filtering firewalls.

Proxy firewall can also be called proxy server, its security is higher than packet filtering products, and has begun to develop to the application layer. The proxy server is located between the client and the server, which completely blocks the data exchange between the two. From the client point of view, the proxy server is equivalent to a real server; from the server point of view, the proxy server is a real client. When the client needs to use the data on the server, it first sends the data request to the proxy server, and then the proxy server requests the data from the server according to this request, and then the proxy server transmits the data to the client. Because there is no direct data channel between the external system and the internal server, it is difficult to harm the enterprise internal network system by external malicious attacks.

The advantage of proxy firewall is high security, it can detect and scan the application layer, and it is very effective to deal with the intrusion and virus based on the application layer. Its disadvantage is that it has a great impact on the overall performance of the system, and the proxy server must be set up one by one for all the application types that the client may produce, which greatly increases the complexity of system management.

The former is represented by Checkpoint firewall of Israel and PIX firewall of Cisco company, while the latter is represented by Auntlet firewall of NAI company of USA.

According to the location of the firewall, firewalls can be divided into external firewalls and internal firewalls.

The former establishes a protective layer between the internal network and the external network to prevent the attack of "hackers" by monitoring and restricting all incoming and outgoing communications, blocking external illegal information and controlling the disclosure of sensitive information; the latter divides the internal network into multiple Lans, thus limiting the losses caused by external attacks.

At this point, I believe that everyone has a deeper understanding of "what the firewall can be divided into according to the data processing method of the firewall". You might as well do it in practice. Here is the website, more related content can enter the relevant channels to inquire, follow us, continue to learn!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.