common firewalls

As for server security, one of the most common problems novice encounters is: What kind of firewall should we choose? In the face of such a wide range of server firewalls, when the choice is to consider the visibility of the manufacturer or the firewall itself performance? is the choice of domestic firewall or foreign firewall? Should you use a fee-based enterprise firewall or try a free firewall? These pro

play games with security software such as firewalls. That is to say, I pretend to be an attacker to test whether these security systems can block my attacks or leave my traces in the security system logs. From another perspective, you may be able to discover security vulnerabilities in your enterprise. There are many similar options. Due to space limitations, we cannot elaborate too much. I will illustrate it with some

Most software-only firewalls are based on the PC architecture and may adopt optimized OS as their operating platforms. The features are as follows: good scalability, adaptability, easy upgrade, and far lower cost than the hardware-based firewall. Most hardware-based firewalls use ASIC, and do not require OS support. They feature fast speed, good stability, and higher security factor than software

often use these NMAP commands to improve the security of network deployment. For example, I like to use this command to play games with security software such as firewalls. That is to say, I pretend to be an attacker to test whether these security systems can block my attacks or leave my traces in the security system logs. From another perspective, you may be able to discover security vulnerabilities in your enterprise. There are many similar options

application from attacking, even some network firewalls do not provide the function of data decryption at all. 2, the ordinary application encryption, can easily escape the firewall detection What the network firewall cannot see is more than SSL-encrypted data. Data that is encrypted by the application is also not visible. In most network firewalls today, a static feature library is relied on, similar to

Deep Firewall logging This article will explain to you what you see in the Firewall log (log). Especially what those ports mean ... This article will explain to you what you see in the Firewall log (log). Especially those ports, what do you mean? You will be able to use this information to make a judgment: Have I been attacked by hacker? What does he/she want to do? This article applies both to security experts who maintain an enterprise-class firewall and to home users who use personal

to discover security vulnerabilities in your enterprise. There are many similar options. Due to space limitations, we cannot elaborate too much. I will illustrate it with some common options. 1. segment packets. Similar security devices such as firewalls can be used to filter scan packets. However, this filtering policy is not very secure. If you use the-f option of the NMAP command, you can segment the Tc

the general term of this kind of preventive measures. It should be said that the firewall on the Internet is a very effective network security model, through which it can isolate the risk area (that is, the Internet or a certain risk network) and the security Zone (LAN) connection, without impeding people's access to risk areas. Firewalls can monitor traffic in and out of the network to accomplish seemingly impossible tasks, allowing only secure, app

A more than 200,000 of the hardware firewall, but finally to 80,000 yuan to deal with the price. Behind this huge price gap, what is the truth hidden? And the more and more hot hardware firewalls on the market, are they really worth it? The reporter began to investigate. The "True colors" of the hardware firewall In an enterprise, the reporter saw this value of more than 200,000 yuan in a domestic well-known brand hardware firewall. It claims to suppo

firewall" technology. About these distributed firewall products will be introduced in the next article. As we all know, the traditional border firewall is used to restrict the mutual information access and transfer operations between the protected enterprise internal network and the external network (usually the Internet), where it is located between the internal network and the external network. In fact, all of the different types of firewalls that

classification1) Packet filteringAnalyze IP and port, whether Mac conforms to rules, if compliant, acceptBy source port, source IP, source Mac, package specific tag and directory port, Ip,mac to determine whether the packet can pass through the firewall2) Proxy Server3 Firewall Restrictions1) firewall does not effectively prevent viruses and trojans2) Firewalls do not normally set internal access rules, so they are not valid for internal attacks4 Fir

Firewall: Includes a software firewall (Iptables/netfilter-based packet filtering firewall) and hardware firewall, at the host or network edge of the message through the firewall to detect a certain conditions filtering a series of components.The implementation of firewalls in Linux systems:The use of Iptables/netfilter can not only implement the host firewall (the Security Service scope is limited to a current host), but also can implement the networ

The Cisco router has a very high market demand. Here we mainly introduce the background of Cisco router and firewall. Firewall has become a key part of enterprise network construction. However, many users think that Cisco routers already exist in the network and some simple packet filtering functions can be implemented. So why should we use firewalls? The following is a security comparison between the NetEye firewall and the most widely used and repre

The number of concurrent connections refers to the ability of a firewall or proxy server to handle its business information flow, is the maximum number of point-to-point connections that a firewall can handle at the same time, reflecting the ability of the firewall device to access and link state tracking for multiple connections, and the size of this parameter directly affects the maximum amount of information that the firewall can support. The number of concurrent connections is an important i

Now with people's security awareness, firewalls are generally used by companies to ensure the security of the network, the general attackers in the case of a firewall, generally it is difficult to invade. Here is a firewall environment under the attack and detection. The basic principle of a firewall First, we need to understand some basic principles of firewall implementation. Firewall is currently the main packet filter, and stateful detection pac

Article Title: The relationship between vsFTPd servers and firewalls and SELINUX is ambiguous. Linux is a technology channel of the IT lab in China. Some basic categories include desktop applications, Linux system management, kernel research, embedded systems, and open-source systems. I have seen some brothers on the forum that vsFTPd servers are running normally, but it cannot be accessed or files cannot be uploaded by users. I think it should be a f

How Linux firewalls Open specific portsIptables is a firewall under Linux and is also the service name.Service iptables Status View firewall stateService iptables start to turn on the firewallService iptables Stop shutting down the firewallService iptables Restart Restart firewallFirewalls Open specific ports:① file/etc/sysconfig/iptables② Add:-A rh-firewall-1-input-m state--state new-m tcp-p TCP--dport 8080-j ACCEPT(The number 8080 stands for open 80

When an intranet is connected to the Internet, it is possible to have a physical connection with 50,000 of unknown networks and users, opening these connections to use a wide variety of applications and shared information, although most of the content is certainly not shared with the outside world, and the Internet provides a vast space for hackers to steal information and disrupt the network So security becomes a concern for connecting to the Internet. Why use a firewall

There are some problems that often make users confused: in terms of product functions, the descriptions of various vendors are very similar, and some "coming soon" are extremely similar to well-known brands. How can we identify this situation? Similar Products are described. Even for the same function, individual differences are obvious in terms of implementation, availability, and ease of use. I. Access Control at the network layer All firewalls