Content filter- a device or software for filtering sites by their content, which does not allow access to certain sites or services on the Internet. The system allows you to block websites with content that is not intended for viewing.

The content filter works according to the statistical principle, that is, it counts predefined words of the text and determines the category to which the content of the site belongs. The purpose of such devices or programs is to restrict access to the Internet for schools, businesses, religious organizations, etc. Most often, content filters are used to restrict access for children and adolescents, in educational institutions, libraries and workplaces in various institutions, and also gaming clubs and internet cafes.

Principle of operation
Often filtering takes place at the level of HTTP requests. To do this, the URL of the requested site is checked against the blacklist using regular expressions. Such lists need to be updated regularly; protection with their help is considered ineffective. More advanced methods are pattern recognition and natural language processing. To classify sites according to different criteria (for example, “pornography / non-pornography”, “warez / freeware directory”, etc.), the text of the requested page is analyzed for the number of different keywords (for example, “free”, “download”, etc.). d.). These and other text properties are used to calculate the probability of falling into a dangerous category. If this probability exceeds a given level (for example, 95%), access to the page is blocked.

The simplest programs allow you to enter words that the system will search for manually. The most complex devices already have a large vocabulary and require a ready-made reference base that is already classified. As a rule, manufacturers provide periodic updating of the link base for complex devices. Those websites that were not automatically recognized are viewed by a person and manually assigned the category of the site.

An obvious requirement for access restriction programs is classification speed.

NetPolice Lite

A light version of a personal filter that provides the most important functions for restricting user access to negative, unwanted and dangerous Internet resources. The most necessary categories and functions for the safe use of the Internet are supported.

KinderGate

a paid program that has a wide range of features and flexible settings.

http://www.kindergate.ru/ - Program site.

http://www.kindergate.ru/support/kindergate_setup - installation instructions.

http://www.kindergate.ru/support - Technical documentation for setup and installation.

http://www.kindergate.ru/download/ - Here you can download the program.

WebOfTrust + AdBlock

free web browser extensions to help protect your child from inappropriate content.

http://www.mywot.com/ru - Program site.

http://www.mywot.com/ru/faq - Questions and answers.

To install this protection tool, you need:

1. Follow the link http://www.mywot.com/ru/download and download the add-on for your browser
2. Follow the instructions during installation.
3. During the installation of the add-on, you can register as a user. You can use the WOT add-on and also rate websites without registration.

Registered users have more customization options.

In order for the user to be safe on the network, special programs have been developed to filter traffic and web content.

How content filtering works

The main purpose of a content filter is to restrict access to prohibited or malicious resources. This is achieved with the help of lists of allowed/prohibited resources.

Every user needs protection, but children and teenagers especially need it. Indeed, on many pages there are scenes of violence, erotica, advertising of harmful substances and alcohol. To protect children from such information, it is necessary to use a content filtering system.

Internet traffic filtering

Our company has developed a special mechanism for filtering Internet traffic, which not only helps maintain network access in working order, but also ensures the continuity and integrity of business processes. The web filter allows you to control the flows entering the local network, automatically reducing its load. At the same time, the problems of inappropriate access to extraneous resources, irrational use of the network and working hours are removed.

An Internet traffic filtering system is needed at different levels: for home use and for a corporate network. It exists in different forms:

• utilities;
• applications;
• browser add-ons;
• separate server.

A-Real Consulting is actively developing various ways to ensure network security, providing customers with a comprehensive solution. We have extensive experience in implementing Internet content filtering systems in schools and organizations.

Our content filter works based on web traffic data reported by the proxy server module. Then there is a reconciliation with the list of prohibited resources. This database includes several million sites divided into categories, which allows you to individually configure web content filtering options.

Users of the filtering system from Internet Control Server simply need to disable a category, and all sites of this subject will automatically become inaccessible.

Content filtering also includes anti-virus modules, automatically checking all incoming traffic for malware. Our solution guarantees reliability and security by providing all the tools to manage network access.

Content filtering in schools and educational institutions

According to statistics, more than 100,000 educational institutions have access to the Internet, where students are exposed to a stream of aggressive and potentially dangerous content. Therefore, the Federal System for exclusion of access to Internet resources incompatible with the tasks of upbringing and education of students of the Russian Federation (SID) was approved and approved.

In accordance with Federal Law No. 436 “On the Protection of Children from Information Harmful to Their Health and Development” and Federal Law No. 139 “On Amendments to the Federal Law “On the Protection of Children from Information Harmful to Their Health and Development”, setting content filtering in an educational institution is a mandatory requirement.

Possible options

Internet filters can be configured in 2 ways:

1. contact your Internet service provider for help;
2. install and configure specialized software.

In the second case, you will have to download and configure the content filter for a school or other organization yourself. Our company offers to use the Internet gateway ICS. It is regularly updated and contains addresses of resources with information whose distribution is prohibited in the Russian Federation, i.e. complies with Federal Law No. 139 "On Black Lists".

ICS functions for content filtering

• organization of access only to reliable resources;
• filtering access to resources from the list of the Ministry of Justice;
• restriction of access by URL, keywords, patterns, regular expressions;
• the ability to create your own prohibiting and allowing rules;
• ready-made sets of rules for schools (just turn them on) and a registry of safe educational sites;
• security from malicious objects that seek to get into the local network, carried out using the built-in firewall;
• control of user access to the network;
• keeping records of consumed traffic.

Benefits of ICS Internet Gateway

• the possibility of preliminary evaluation and testing using a demo version for 35 days;
• unlimited term of the licensed version;
• accessible training in the form of videos;
• free full Lite version up to 8 users;

ICS setting

Another advantage of ICS is the ease of installation and configuration. To do this, you need to perform only 5 actions:

This is how you can easily set up Internet filtering, providing full protection against external threats.

Free internet filter

Filtering online content has become a real necessity, as the variety of information on the Internet is dangerously large even for an adult. The use of special traffic analysis and filtering programs helps prevent unwanted information from appearing on the user's screen and restricts access to dangerous resources.

Opportunities

The Internet Control Server program has a wide range of options for filtering Internet content, becoming an obstacle to dangerous traffic already at the edge of the local network. To evaluate the full set of tools, you can download a free trial version, limited only by the time of use, but not by functionality.

With the advent of federal law No. 436-FZ, content filtering systems in schools have become not only a mandatory element, but are also subject to reliability checks. The ICS program complies with all requirements established by law for such software products. The solution uses complex technologies, but the program is simple and understandable to the user without special knowledge. Together with technical support, you get a reliable and modern content filtering system for a school, office or home.

Main functions of ICS

As a content filter:

• Filtering traffic from any source.
• Search requests go through SkyDNS, a Russian Internet service specially created for filtering tasks and working very efficiently.
• The database of prohibited resources is constantly updated.
• Scanning incoming traffic for inappropriate content.

In general, "Internet Control Server" is essentially a VPN server, and solves all the tasks that are typical for organizing a full-fledged and secure local network:

• certified as a firewall that blocks external threats;
• has a built-in antivirus;
• allows you to manage the network unlimitedly - to delimit the rights and capabilities of users, to take into account traffic, to keep statistics of visited resources, to limit network activities by time, to connect remote users and entire networks, etc.

Ultimately, the management of the educational institution covers all the needs for organizing a local network of an educational institution - from content filtering to absolute control over events occurring on the network.

There is a lot of good and useful information on the Internet. Now people are more likely to look on the Internet to find out the latest news, weather forecast, see the video (instructions on how to do something), cooking recipes, or just to find out how to screw a light bulb into a chandelier. There is a lot of information on the Internet, just manage to enter all kinds of queries into the Yandex or Google search box. But among the useful information, there is harmful and obscene in the form of images, obscene text and videos.

It is very important to protect children from such content, since recently a lot of information has appeared that violates the child's psyche beyond recognition. First of all, of course, you need to monitor the parents of the child at home, and the teachers at school for what sites he visits on the Internet, conduct conversations, and so on.

But not always, it turns out, to keep track of the child, so there are content filtering systems (SKF). Today, the SCF information technology market offers a lot, for example, one of the popular services SkyDNS is a paid and partly free content filtering system for schools, offices and homes.

You can also use the absolutely free Internet access system -.

What is Rejector DNS server and its functionality

- a centralized system of content filtering and Internet access control, with which you can create protection for children from obscene information, images, videos and prohibited sites (+18) and plus protection from viruses (since such sites often contain malware). Simply put, Rejector is a DNS server with the ability to manage it remotely and centrally.

The Rejector service has the following features:

• Support for static and dynamic IP address (IP address from which requests are processed);
• Filtration categories (office filter, children's filter, individual filter);
• Exceptions (black and white list);
• Bookmarks (you can save a long site URL under a short name);
• Statistics;
• Feedback from the administrator with network users;
• Time interval (you can set the days and times for filtering).

How the Rejector service works: registering, configuring and launching content filtering

To use all the functions of the Rejector service - blocking unwanted sites and content, you need to register by providing all the necessary data.

After registration, the control panel of the content filtering system will become available to you. And you can start managing the web service. Everything happens centrally, that is, from your computer.

Section "Networks"

First of all, go to the section "Networks" and make settings:

1. Enter the name of your network (any name, you can use Cyrillic or Latin).
2. Select the status: static IP address or dynamic IP address. It all depends on the settings of your provider. You need to check with the provider what address you have.

Explanation :

A static IP address is the permanent address of your computer with no time limit when connected to the Internet. It is issued by the provider and is mainly prescribed by the user in the settings of the computer or router.

A dynamic IP address is a non-permanent (changeable) computer address that is assigned automatically when the device is connected to the network and is used for a certain period of time.

With a static IP address, everything is simple, it is displayed in the upper right corner. You need to copy and paste it into the Ip-address field or look.

With dynamic addresses, everything is much more difficult, because they can change every day, and for some providers it is written in the settings that every 3-4 hours.

To set up a dynamic IP address, it is recommended to use the web service dyn.com/DNS/, although as I noticed, it became paid. You can also search free dyndns online. Users of Windows operating systems can use Rejector Agent .

In the following articles, I will try to write how to set up automatic detection and updating of dynamic addresses.

Chapter "Filtration" you can choose the white and black list that suits you, according to which the content will be filtered. There are ready-made ones: an office filter, a children's filter, a bladeless filter and others.

By choosing you can configure content filtering according to individual settings, that is, select the categories of sites that will be blocked.

In chapter "Exceptions" you can refine the list of sites that need to be blocked, or vice versa, to which there must be mandatory access on the Internet. In simpler terms, the refinement of the white and black lists.

Section "Bookmarks"

Section "Statistics"

The "Statistics" section is designed to track the number of requests for site URLs, blocked web resources, erroneous requests for a certain period of time (the user can set the period of time he needs).

Section "Requests"

In the "Requests" section, the administrator receives messages from network users on a request to open (unblock the site). Users can submit requests from the block page. By the way, the blocking page can be configured in the "Networks" section by clicking on the link Tune on your ban page.

Section "Time interval"

The "Time interval" section is devoted to settings with the time of content filtering in the network. For example, you can configure the Rejector service not to block sites after 17:30, etc.

To clear the cache in Windows, you need to run the command ipconfig /flushdns.

After the actions described above, we can say that most of the work has been done to fully filter the content.

It remains to configure the network adapter in the operating system that is installed on your computer or make settings in the router (router).

Configuring the network adapter and router (router)

There is nothing left to fully launch the Rejector content filtering system on your computer or in an organization (office, school). You need to register the Rejector DNS servers: 95.154.128.32 and 78.46.36.8. Without this, it will not be possible to filter prohibited sites and content.

Configuring DNS servers to use Rejector on Windows (Windows XP, Windows Vista and Windows 7) is written. Therefore, I see no point in writing a new instruction. There is a step by step guide with screenshots.

But I did not find the settings of routers for Rejector on their website. There are a lot of routers and therefore it is not possible to describe each router. The example shows instructions for setting up a router (router)D-Link DIR-300NRUB5.

Next, the administrative panel of the router will open in all its glory, where you can make settings. If your router is already configured by your provider or by you yourself and you have access to the Internet, then you need to make changes to the name servers (in this case). To do this, go to the "Advanced" menu section and select "Name Servers". Next, as shown in the screenshot, we enter the Rejector DNS server: 95.154.128.32 and 78.46.36.8 .

Save the changes and reboot the router for the settings to take effect!

For example, I recently set up . In the control panel of this router, you need to go to the menu section "Network", Further WAN and into the fields preferred and alternate DNS server enter the appropriate DNS server Rejector.

If there are problems in configuring the router, write in the comments below, we will try to help you set up contextual filtering.

If you do not want to spend money on a content filtering system for your home, small office or school (educational organization), then the Rejector service will be the right tool for you to block computers from inappropriate content on the Internet.

Write in the comments how you protect your children and what tools you use to block unwanted sites on your computer.

In this article, we will look at a multi-platform (Linux, Windows) solution for effective content filtering, its installation and configuration. Such a filter can be used in schools or other educational institutions.

Introduction

First, a little theory, if anyone is not interested, you can move on to the next chapter. What kind of filtering is there? Traffic filtering can be of two types, server and client.

How server filtering works

There is a dedicated computer, the Internet is configured on it, and this Internet is distributed to other computers via the local network. Filtering takes place on a dedicated computer. Known programs for organizing server-side content filtering:

For :

• UserGate
• Kerio
• ISA Server
• SafeSquid
• Many proxies can be entered here, on which filtering can be organized.

But there is one big drawback for solutions for Windows OS, all of them are almost paid, and if they are free, like the IFF, they require the installation of a paid product.

For Linux:

• DansGuardian
• Mindwebfilter
• and etc.

These programs are free. But they are more difficult to set up.

How client filtering works

On each computer where content filtering is needed, a program that does this is installed and configured. Examples:

Windows

• censor;
• netpolice;
• KinderGate, etc.

linux

• netpolice ALT Linux, etc.

Theory

And now let's talk about a fairly simple free method of content filtering, but at the same time quite effective. I have tried many content filtering methods over the years, but this one has proved to be one of the best and easiest solutions. It can also be used along with any of the other methods as a supplement.

What do we need for this

• Any of the OS: windows or;
• Mozilla Firefox browser or browsers based on it that support Firefox plug-ins and extensions;
• Internet connection.

How it works?

The Mozilla Firefox browser has many add-ons. Based on such additions, we will do content filtering.

Description of add-ons

The first addition on our list is WOT.

WOT (web of trust) is a free browser add-on that warns the Internet user while searching for information or making purchases about potentially unsafe web pages. WOT is compatible with such browsers as Internet Explorer, Mozilla Firefox, Opera (in version 11 using an extension) Chrome. wikipedia

This plugin also has parental controls. With this plugin we will perform content filtering.

Second addition. Adblock Plus

Adblock Plus- an extension for browsers and other software based on Gecko: Mozilla (including "mobile"), Mozilla Thunderbird, Mozilla Suite, SeaMonkey, Songbird and Mozilla Prism, which allows you to block the loading and display of various page elements: excessively annoying or unpleasant advertising banners, pop-ups and other objects that interfere with the use of the site. wikipedia