【正文】 rewall after firewall technology has made rapid development. Dozens of domestic and foreign panies launched the function of the firewall is not the same product range. 5 firewall at the work layer security system at the bottom of belonging to the work layer security technology areas. In this layer, the businesstosecurity system raised of the question: whether all the IP can visit to the enterprise39。s attention to the work security products in one. Although theoretically, firewall work security at the bottom, the work responsible for the security authentication and transmission, But with work security technology development and application of the work changes, Modern technology has gradually firewall to the work layer other than the safety level, not only to plete the traditional firewall filtering tasks, but also for the various works to provide the corresponding security services. In addition there is many other firewall products are moving towards data security and user authentication, antivirus and hacker intrusion direction. SMEs in the specific work environment, in addition to HIV and the birthright of transmissibility, enforceability, and conventional destructive virus in mon, but also have some other features: 1. Faster rate of infection The spread of the virus must be some means for the plete closure of the single case。s work statistics, the virus has been removed, 85% of the 30 days will be reinfection. Enterprises still using single version of antivirus software virus defense at the same time, virus has in various forms through the LAN to spread quickly, and they attacked the client, server, and gateway, almost all pervasive. it is not exaggerating to say, we can easily make the entire LAN gridlock, should we really have to sit until death? Although the prospect of using virus technology to simplify the task of delivering patches and software updates is tempting, the dangers can outweigh the benefits when the process is too automated. For example, the improved Windows Update feature in Windows XP now allows patches and updates to be downloaded automatically, although installation is still at the user’s discretion. Trojan horses, worms, and other malicious code forms have proven to be incredibly successful at paralyzing systems and Inter providers. It is therefore only logical to conceive of ways to use them for productive purposes, much as the Bible exhorts its readers to beat their swords into plowshares and their spears into pruning hooks. Granted, it would be wonderful if IT administrators could distribute patches and software updates to desktops and servers as quickly as an virus can spread from one machine to the next. But is such a magic wand really a good idea? Well, maybe not exactly. After all, unlike the human immune system, which produces defenses, or antibodies, automatically, the puter must wait for a human to analyze samples of a puter virus, prepare antidotes and vaccines for that specific situation, and only then apply the cure. This observation alone would seem to discredit the idea of a “digital immune system” that the security munity has tossed around during the past few years, but 5 there’s an even more important point to consider. Similar to the way that autoimmune diseases turn the body’ s own defenses against itself, so could one turn a viruslike software delivery system against its own puters. Although it would be difficult to monkey with the digital certificates that would conceivably be used to identify trusted patches, it’s not impossible to subvert the certificate issuing system. Viruses, worms, and Trojan horses are programs created by hackers that use the Inter to infect vulnerable puters. Viruses and worms can replicate themselves from puter to puter, while Trojan horses enter a puter by hiding inside an apparently legitimate program, such as a screen saver. Destructive viruses, worms, and Trojan horses can erase information from your hard disk or pletely disable your puter. Others don39。s performance and stability. Antivirus programs scan and other file