What kind of security model is firewall technology?
The so-called firewall refers to a protective barrier composed of software and hardware devices and constructed on the boundary between the internal network and the external network, and between the private network and the public network.
A firewall is a technical measure to protect computer network security. It isolates internal and external communications by establishing a corresponding network communication monitoring system at the network boundary. External network to block network intrusions from the outside. (Recommended learning: web front-end video tutorial)
Firewall technology was originally a protective measure taken against Internet network insecurity. As the name suggests, a firewall is an internal network barrier used to block the influence of external insecure factors. Its purpose is to prevent unauthorized access by external network users.
It is a combination of computer hardware and software that establishes a security gateway (Security Gateway) between the Internet and the Internet to protect the internal network from intrusion by illegal users. The firewall is mainly composed of service access policies It consists of four parts, verification tool, packet filtering and application gateway. A firewall is a piece of software or hardware located between a computer and the network it is connected to (hardware firewalls are rarely used and are only used by the Department of Defense and other places because of their price. expensive).
All network traffic to and from this computer must pass through this firewall.
Firewalls include network firewalls and computer firewalls. Network firewall refers to setting up a network firewall between the external network and the internal network. This kind of firewall is also called a filtering router.
The network firewall detects the protocol, destination address, port (network layer) and transmitted information form (application layer) of incoming information, and filters out external information that does not comply with regulations.
Computer firewall refers to setting up a firewall between the external network and the user's computer. Computer firewalls can also be part of the user's computer.
The computer firewall detects the interface procedures, transmission protocols, destination addresses and/or transmitted information structures, etc., and eliminates incoming information that does not meet the regulations. The computer firewall checks the information output by the user's computer and adds the corresponding protocol layer flag to transmit the information to the receiving user's computer (or network).
The benefits of using firewalls include: protecting vulnerable services, controlling access to systems, centralized security management, enhancing confidentiality, recording and counting network utilization data and illegal use of data. There are usually two basic design strategies for firewall design: first, allow any service unless explicitly prohibited; second, prohibit any service unless explicitly permitted. The second strategy is generally used.
From a technical perspective, there are two types of firewalls, namely standard firewalls and dual-hole gateways. Standard firewalls use specialized software and require a relatively high level of management, and there is a certain delay in information transmission.
Dual-hole gateway is an expansion of the standard firewall, also known as the application layer gateway. It is a separate system, but it can complete all the functions of the standard firewall at the same time. Its advantage is that it can run more complex applications while preventing any direct connection between the Internet and internal systems, ensuring that data packets cannot directly reach the internal network from the external network.
The above is the detailed content of What kind of security model is firewall technology?. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undress AI Tool
Undress images for free
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
How to fix 'Error: 0x80070185, Cloud operation was unsuccessful” in OneDrive
May 16, 2023 pm 04:26 PM
OneDrive is a popular cloud storage application provided by Microsoft. Most of us use OneDrive to store our files, folders, documents, etc. But some users complained that when they try to access shared files on OneDrive, it gives an error stating “Error: 0x80070185, Cloud operation was unsuccessful”. Therefore, they cannot perform any operations on OneDrive such as copying files, pasting, downloading shared files, etc. Nowadays, it is necessary to use these operations in our daily work. This error can be easily solved and for this we have some methods that we can apply and try to solve the problem. let's start! Method 1 – Sign out and sign back in to OneDrive app steps
How to solve if Edge browser is blocked by firewall?
Mar 13, 2024 pm 07:10 PM
How to solve the problem that the Edge browser is blocked by the firewall? Edge browser is Microsoft's own browser. Some users found that this browser was blocked by the firewall during use. So what's going on? Let this site give users a detailed introduction on how to recover the Edge browser if it is blocked by the firewall. How to restore the Edge browser if it is blocked by the firewall? 1. Check the firewall settings: - Click the "Start" button on the Windows taskbar, and then open "Settings". -In the Settings window, select Update & Security. -exist
Win11 firewall advanced settings gray solution
Dec 24, 2023 pm 07:53 PM
When setting up the firewall, many friends found that their win11 firewall advanced settings were grayed out and unable to be clicked. This may be caused by not adding a control unit, or by not opening the advanced settings in the correct way. Let’s take a look at how to solve it. Win11 firewall advanced settings gray method one: 1. First, click the start menu below, search and open "Control Panel" at the top 2. Then open "Windows Defender Firewall" 3. After entering, you can open "Advanced Settings" in the left column . Method 2: 1. If the above method cannot be opened, you can right-click "Start Menu" and open "Run" 2. Then enter "mmc" and press Enter to confirm opening. 3. After opening, click on the upper left
8 Big Fixes if Grammarly Not Working on Windows 10 Browser
May 05, 2023 pm 02:16 PM
If you have syntax issues on your Windows 10 or 11 PC, this article will help you solve the problem. Grammarly is one of the most popular typing assistants for fixing grammar, spelling, clarity, and more. It has become an essential part of writing professionals. However, if it doesn't work properly, it can be a very frustrating experience. Many Windows users have reported that this tool does not work well on their computers. We did an in-depth analysis and found the cause and solution of this problem. Why doesn't Grammarly work on my PC? Grammarly on PC may not work properly due to several common reasons. It includes the following
Resolve error code 0xc004f074 when activating Windows 11.
May 08, 2023 pm 07:10 PM
After installing the latest operating system on your PC, activating your copy of Windows 11 is the main job. Not only does it unlock the true potential of the Windows 11 operating system, but it also gets rid of the annoying "Activate your Windows 11" message. However, for some users, Windows 11 activation error 0xc004f074 hinders the smooth progress of activation. This bug apparently prevents users from activating Windows 11 and forces them to use an operating system with limited functionality. Windows 11 activation error code 0xc004f074 is related to the Key Management Service. You will encounter this problem when KMS is unavailable. Okay, that's it for this tutorial
How to enable or disable firewall on Alpine Linux?
Feb 21, 2024 pm 12:45 PM
On AlpineLinux, you can use the iptables tool to configure and manage firewall rules. Here are the basic steps to enable or disable the firewall on AlpineLinux: Check the firewall status: sudoiptables -L If the output shows rules (for example, there are some INPUT, OUTPUT, or FORWARD rules), the firewall is enabled. If the output is empty, the firewall is currently disabled. Enable firewall: sudoiptables-PINPUTACCEPTsudoiptables-POUTPUTACCEPTsudoiptables-PFORWARDAC
How to remove the firewall logo on the Win10 desktop icon?
Jan 01, 2024 pm 12:21 PM
Many friends who use win10 system find that there is a firewall logo on the icon on the computer desktop. What is going on? This makes many friends with obsessive-compulsive disorder particularly uncomfortable. In fact, we only need to open the control panel and click " It can be solved by changing "Change User Account Control Settings". Let's take a look at the specific tutorial. How to cancel the firewall logo on the desktop icon in Windows 10 1. First, right-click the Start menu button next to the computer startup screen, and then select the Control Panel function from the pop-up menu. 2. Then select the "User Account" option and select the "Change User Account Control Settings" item from the new interface that appears. 3. After adjusting the slider in the window to the bottom, click Confirm to exit.
How to fix UFW status showing as inactive in Linux
Mar 20, 2024 pm 01:50 PM
UFW, also known as Uncomplex Firewall, is adopted by many Linux distributions as their firewall system. UFW is designed to make it easy for novice users to manage firewall settings through both the command line interface and the graphical user interface. A UFW firewall is a system that monitors network traffic according to set rules to protect the network from network sniffing and other attacks. If you have UFW installed on your Linux system but its status shows as inactive, there could be several reasons. In this guide, I will share how to resolve the UFW firewall inactive issue on Linux systems. Why UFW Shows Inactive Status on Linux Why UFW Is Inactive by Default on Linux How to Inactive on Linux