What functions does the windows firewall perform? Firewall - what is it? Standard PC Defender

Hi all! Want to know what a firewall is on a computer? Then read the article below! “Firewall” or “Firewall” is a set of programs that serves to protect computer system from hacker attacks and hacking, as well as viruses and other malware.

What is a firewall on a computer?

"Firewall" increases the level of security in the network and repels all kinds of attacks on the system. Remember, you don't need to disable the Firewall. If you do not like this complex, then install another one with third party resources. But complete shutdown The standard "Firewall" is dangerous for the system.

« Firewall» monitors and blocks legitimately serious connections and ensures the protection of user data. Do not confuse it with antiviruses, which are designed to combat malicious programs that have penetrated the system or removable media. Antiviruses are not configured to suppress network attacks. And “Firewall” monitors traffic on the network. Would you like complete safety systems? Using a Firewall and an antivirus at the same time provides a greater guarantee of PC security.

Purpose of the Firewall

What are the tasks of the “Firewall”:

• Monitoring suspicious connections. There are programs that try to send information to the Internet and receive various other information from the Internet. When it's programs like " Outlook Express", "MSN" and other well-known ones, then there are no problems. But if suddenly some unknown suspicious program, then it could be a Trojan.
• Blocking all ports that are not involved in operation and analyzing traffic from open ports. Communication between the Internet and the computer is carried out using ports, through which the system can also be attacked. “Firewall” in this case protects the ports and warns about attempts to penetrate malicious traffic.
• Monitoring running programs. If there is any change in the important data of previously running programs, “Firewall” warns about it.

Without a Firewall, in a couple of minutes on the Internet you can easily pick up viruses and other malware.

Working with Firewall

Windows has a standard “Firewall” that has quite broad functionality and an expanded interface that allows you to create additional rules, for example, blocking connections to the network of any programs or allowing applications to communicate only with certain addresses.

You have the opportunity to use a third-party program that complements the Firewall functions. For example, they recommend the program “ Windows Firewall Control". Next, I will show the use of the “Firewall” using the example of dozens of operating systems. In other versions of the system the actions are similar.

Connecting and disconnecting

• Go to “Control Panel”, and then “System and Security”> “Windows Firewall”> “Turn Windows Firewall on or off”. Move to " Enable Windows Firewall", "Settings for a private network" and "Settings for public network" Confirm by clicking "Ok".
• Another way to open the settings is to use the “firewall.cpl” command in the Run program, which can be launched through the “Win” and “R” buttons. They must be pressed simultaneously.

Adding exceptions

If you enable a program lock that you need to functionality, include it in the exceptions by following the appropriate steps:

• Opening " Firewall" in the "Control Panel" and select there "Allow interaction with an application or components in the Windows Firewall."
• Instructions to “Change settings” and “Allow other apps.”
• Click "Browse".
• Choice the desired program and confirmation - “Add”.
• Check the boxes for “Public” and “Private” networks opposite the program.
• Save the settings by clicking “Ok”.

Conclusion

So you have learned what a firewall is on a computer. The question is very interesting and informative. Feel free to leave your comments. We will be happy to help you resolve the issue. Thanks everyone for your attention! Good luck and peace to you!

Continuing the topic of computer security, in this lesson we will look at the main purpose of the Windows 7 firewall.

Probably each of you was interested in this name. For a more detailed picture and purpose of the firewall, let’s imagine that our computer has access to the Internet, and we are on the World Wide Web.

It doesn’t matter whether we work there or just relax, the main thing is that our computer is connected to the network. Various packet exchange processes occur on the computer ( this term we'll cover it in the next lessons, don't miss it, so subscribe to updates). So, there is a possibility that people who are engaged in data theft and are also capable of causing harm can connect to our computer operating system, launch your virus.

In other words, your computer may be hacked. To prevent computer hacking, various programs and physical means are used that control the operation of incoming and outgoing processes; such means are called firewalls.

It should be noted that thanks to firewalls, the security of working on the network increases, and most attacks on the computer are repelled by filtering some information packets. Therefore, I strongly recommend that you do not disable the firewall. If you have it turned off, be sure to turn it on. As you can see, the firewall serves additional protection your computer from outside influence.

To open the firewall, follow the following commands: Start – Control Panel – System and Security – . In this explorer, you can view the firewall settings and make settings, as well as view notifications. To enlarge the pictures, just left-click on them!

So, let's look at the basic firewall settings that help ensure normal functioning both the computer and programs that provide data transfer over the network.

Firstly, it should be noted that there are situations when a firewall blocks data exchange on the Internet.

In this case, it will be necessary to indicate to the firewall the programs that can exchange information, that is, to allow data exchange.

To do this, you will need to open a window by clicking the “Allow a program or component through Windows Firewall” link and check the appropriate boxes next to each program.

Enabling or disabling the firewall is done by clicking on the link “Turn Windows Firewall on or off”

In the window that opens, you can configure the following parameters:

1. Setting up a domain profile
2. View and configure connection rules.
3. Create a specific rule for a secure connection.

Well, in conclusion, let’s look at how you can implement automatic update .

Occasionally Microsoft company releases updates to the operating system, in which specific programs and algorithms are refined, and the system’s protection against hacking is improved and improved. The operating system is updated automatically, although you may need to restart your computer for the changes to take effect.

So how can you set up automatic updates?

To do this you need to do following commands: Start - Control Panel - System and Security - Windows Update.

As a result, a window will open that contains basic information about the updates being installed, and also allows you to necessary settings. First of all, you will need to activate automatic updates (if you do not already have it activated). To do this, in the left part of the window, click on the “Settings” link; a window will open in which you will need to specify the method for installing the update. By default, it is recommended to select "install automatic updates (recommended)".

This is what we set up for you" Important updates", they provide reliability and improve computer protection. Next, you should check the box “Receive recommended updates”, which are also additional funds in terms of increasing reliability.
As you can see, everything is extremely simple, activate the update, indicate the time for installing the updates. For today, that’s all I wanted to tell you about the Windows 7 firewall, see you in the next lesson!!

And for dessert, here’s a video joke for you

A firewall, or firewall, is a system that provides network security by filtering incoming and outgoing traffic, guided by user installed rules. The main purpose of a firewall is to eliminate or reduce unwanted network communications. In the majority server infrastructures Firewalls provide a basic layer of security that, when combined with other precautions, can help prevent malicious attacks.

This article explains how firewalls work, specifically stateful software firewalls (such as IPTables and FirewallD), as they relate to cloud servers. The article covers TCP packets, different types of firewalls, and many other topics related to stateful firewalls. In addition, at the end of the manual you can find many useful links for manuals that will help you configure a firewall on your server.

TCP network packets

Before we start the discussion various types firewalls, become familiar with Transport Control Protocol (TCP) traffic.

TCP network traffic travels across the network in the form of container packets containing headers that contain control information (source and destination addresses, sequence of information packets) and data (called payload). The control information in each packet ensures that its data is delivered as expected and that its elements also support firewalls.

It is important to note that in order to successfully receive an incoming TCP packet, the recipient needs to send acknowledgment packets back to the sender. Combination control information in incoming and outgoing packets can be used to determine the state of the connection.

Types of firewalls

There are three basic types of firewalls:

• packet filters network layer(or stateless),
• stateful (or stateful),
• And application level.

Network layer packet filters work by analyzing individual packets. They are unaware of the connection state and can only allow or deny packets based on their individual headers.

Stateful firewalls can detect the connection state of a packet, making them more flexible. They collect packets until they determine the state of the connection before firewall rules are applied to the traffic.

Application layer firewalls analyze the transmitted data, which allows network traffic through firewall rules specific to individual services and applications. They are also known as proxy firewalls.

Except software firewalls available in all modern operating systems, firewall functionality can also be provided by hardware devices (such as routers or hardware firewalls).

Firewall rules

As mentioned above, the network traffic that passes through the firewall is inspected using sets of rules to determine whether the traffic is allowed or not. The easiest way to explain firewall rules is with examples.

Let's say you have a server with a list of rules for incoming traffic:

1. Accept new and previous established traffic on network interface via port 80 and 443 (HTTP and HTTPS web traffic).
2. Drop incoming traffic from IP addresses of non-technical office employees to port 22 (SSH).
3. Accept new and existing incoming traffic from the office IP range to the private network interface via port 22 (SSH).

Notice the words "accept" and "drop" in these examples. With their help, you specify the action that the firewall should perform if the traffic matches the rule.

• Accept means to allow traffic;
• Reject – block traffic and return an “unreachable” error;
• Drop – block traffic and return nothing.

Network traffic passes through a list of firewall rules in a certain sequence, which is called a chain of rules. Once the firewall detects a rule that matches traffic, it takes the appropriate action on that traffic. IN in this example According to the firewall rules, an office employee trying to establish an SSH connection to the server will be blocked according to rule 2 and will not be allowed to access rule 3. System Administrator it will pass the firewall because it meets rule 3.

Default firewall policy

Typically, firewall rule chains do not cover everything possible conditions obviously. Therefore, chains should always have a default policy, which consists of only actions (accept, reject or drop).

For example, the default policy of one of the previously mentioned chains is drop. If any computer outside the office tries to make an SSH connection to the server, the traffic will be dropped because it does not match any rules.

If the default policy is set to accept, then any user (except non-technical office staff) will be able to establish a connection with any open service of this server. Of course, this is an example of a very poorly configured firewall because it only protects services from non-technical people.

Incoming and outgoing traffic

Network traffic, from the server's point of view, can be either incoming or outgoing; The firewall maintains a separate set of rules for each type of traffic.

Traffic that originates from anywhere on the network is called incoming traffic. It is treated differently from outgoing traffic that is sent by the server. Typically, a server will allow outgoing traffic because it considers itself trustworthy. However, a set of outbound rules can be used to prevent unwanted communication in the event that the server is compromised by an attacker or a malicious executable.

To take full advantage of a firewall's security, you need to identify all the ways other systems can communicate with your server, create rules that explicitly allow that interaction, and then drop all remaining traffic. Keep in mind that you also need to create appropriate rules for outgoing traffic so that the server can send confirmations for allowed incoming connections. Additionally, keep in mind that the server typically needs to initiate its own outbound traffic (for example, to download updates or connect to a database), so it is important to think through these cases and create a set of rules for them.

Creating outbound rules

Let's assume the firewall drops outgoing traffic by default (drop policy). Therefore, accept rules for incoming traffic will be useless without additional rules outgoing traffic.

To complement the previously mentioned inbound rules (1 and 3) and ensure proper interaction with these addresses and ports, you can use the following outbound firewall rules:

• Accept existing outgoing traffic on the common network interface via port 80 and 443 (HTTP and HTTPS);
• Accept existing outgoing traffic on the private network via port 22 (SSH).

Please note that you do not need to explicitly set a rule for dropped incoming traffic (rule 2), since the server will not establish or acknowledge this connection.

Programs and tools

So now you know how a firewall works, it's time to familiarize yourself with the basic packages that allow you to configure a firewall. Below you can read about the most common packages for configuring a firewall.

IPTables

IPTables is a standard firewall that comes by default with most Linux distributions.

Note: A more modern option is called nftables and will soon replace this package.

In fact, IPTables is a front-end for kernel-level netfilter hooks that can be used to control network stack Linux. It works by matching each packet crossing a network interface with a set of rules.

Instructions for setting up the IPTables firewall can be found in the following articles.

A firewall in Windows is a computer security program that inspects and controls outgoing and incoming data (traffic) between the computer and the network. The network can be either a local network or the Internet, which is more common. Without a firewall enabled, all network traffic passes through the PC uncontrollably, while a working firewall, depending on its settings, blocks or allows data to pass through. The enabled firewall together with becomes a real wall from malware and network attacks. By the way, the second name of this type of program is Firewall, which translated from English means “wall of fire.” You can also see the name firewall.

How to enable Windows Firewall

Windows OS has a built-in firewall and it is not always enabled out of the box. Check if the firewall is working by opening the computer Start > Control Panel, switch the window view to show " Large icons " or " Small icons" (for ease of search) at the top right and find the icon " FirewallWindows».

Open the firewall window with the left mouse button. When the firewall is turned on, there will be an image of a green shield opposite the connection. Otherwise you will see a red shield.

If the firewall is disabled, you need to enable it as follows:

Windows Firewall Settings

To configure the firewall, open the firewall window in the control panel, as described above in point No. 1 and click on the “menu” item in the left panel.

Here you can view and set rules for network connections various programs and services. For programs and services built into the operating system, network connection rules are already installed automatically.

For third party programs, after installing them, the first time you access the network, the firewall asks the user to allow or deny access to the network for this program. By allowing or denying access, you give a command firewall create a rule for this application and remember it so that the firewall doesn’t ask you next time. Thus, without your knowledge, no program will receive an Internet connection.

To enable, disable or change an existing rule for a program, find it in the list of rules in additional parameters firewall and double-click it to create a new rule.

To allow network access to a previously installed program, click on the “” menu item in the left column.

In the window that opens, click on the button “ Change settings", then click on the button " Allow another program» open selection window installed applications, find the one you need and give it permission to connect by checking the box next to the name.

Windows Firewall is now enabled, configured, and ready to fend off network attacks.

Sooner or later, every person who actively uses a computer and the Internet asks the question, what is a windows firewall? Not everyone knows how effective this tool is, which can protect your computer from most external problems.

Correctly configured windows firewall in combination with antivirus program, are able to protect your computer from the vast majority of viruses and malicious attacks. What is a firewall and how to work with it, read on...

Windows Firewall, also known as firewall, is a program that checks all data and connections from the Internet that request access to your computer. Depending on your firewall settings, it either allows or blocks data entering your computer.

To put it even more simply, a firewall is a wall between the Internet and your computer.

In the operating room Windows system there is a built-in firewall, but not everyone has it enabled by default and is located in in working condition. If you have a pirated version installed on your computer Windows version, then with a high degree of probability I can say that you have it turned off.

To check the status of your firewall, open the “Control Panel” and find the corresponding icon

By clicking on it, the firewall management window will open. If you see a green shield next to the connection, it means your firewall is enabled.

To configure the firewall, click the “Advanced settings” button in the left column

In this window you can view the rules for incoming and outgoing connections. When you first launch a program that requires an Internet connection, it will prompt you to create a rule for the firewall (provided that the firewall is active).

In addition to third-party programs, connection rules also have built-in windows programs and applications.

To enable or disable a rule, double-click on it; to create a new rule, click right click mouse on the corresponding connection (outgoing/incoming) and select “Create rule”

If you are interested in how to disable the firewall, I will tell you. To do this, return to the main firewall window and select “Enable/Disable Firewall...”

Then I think it’s clear...

Now let's see how this whole thing works. On the test computer I installed a program for downloading torrents - Utorrent. When you first start it, a firewall window appears warning you that the program is trying to access the Internet.

For normal operation program, click “Allow access”. Is it really convenient? Now, without your knowledge, not a single program will be able to connect to the Internet, just as not a single “infection” from the Internet will be able to connect to you.

To add to firewall exceptions already installed program. You need to open “Allow a program or feature to run...”

And there click on “Change settings”, then click on “Allow another program” and select it from the list. If the program you need is not in the list, click the “Browse” button and specify relative path to the program launch file

As you can see, anyone, even the most timid beginner, can configure the Windows Firewall.