Network Scanner - connect, configure, use

Today the answer to a question about what the IP-scanner of a network represents, practically any user can give. This is a sniffer program that identifies a particular computer terminal on a local network or when an Internet connection is established. But how this system works, some can only guess.

What is a network scanner?

Programs or commands of this type can be conditionally divided into several classes depending on the parameters to be determined.

Obviously, the program scanner of the network should work in several modes, including determining the internal and external IP addresses of the connected devices, launching a diagnostics system, recognizing wireless networks and having access to resources based on HTTP and FTP protocols.

Windows Scanning Tools

To determine IP-addresses in Windows-systems, there is a special tool already built into the OS.

As a rule, IP-addresses in their current use by providers are set automatically. In network settings, this setting is simply set (Obtain IP address automatically). In this case, the subnet mask and gateway are installed in the same mode. The DNS server (primary and alternative) is not enabled, in some cases their addresses need to be entered manually, especially if the configuration is done through Google services.

But you can recognize any internal address using the simplest ping command entered in the corresponding console, indicating the internal address of the local computer or terminal connected, for example, to the corporate network.

See all the device addresses currently attached to one of the network protocols, using the ipconfig command.

Many underestimate the command line, and after all, when you specify an add-on to the main command in the form of release6 or renew via a space, you can apply automatic IPv6 settings or even update the configuration to get the DHCP server settings.

External query based on ping command

As for external requests for the ping command, they are mostly made only by the provider or the network administrator.

The disadvantage of this method is the definition of the external IP address of the device connected to the Internet. In this case, the internal address can be hidden or assigned automatically.

And in the case of checking the virtual WLANs, only pinging the router or ADSL modem occurs. Its address does not correspond in any way to the address of the local terminal.

WiFi Scanner

Let's proceed to the software directly. Probably do not need to say that in the same Google Play market you can download a free utility that can recognize virtual networks that are near the user.

But, if you really dig on the Internet, you can find not just a network scanner, but a whole software package that allows you to crack a password or even act as a so-called anonymizer, which somewhat resembles the use of virtual proxy servers and access protocols. The essence of the matter is to determine the unused address and connect to it. Thus, any scanner of IP-addresses on the network makes their determination based on the ones allocated by the provider, although the service itself can only guess at the condition of using a virtual proxy server.

The simplest programs

Among all that today can be found on the Internet, the most popular are the following:

• Free WiFi Detector (scanner of public wireless networks);
• Net Scan - scanner of local ports and IP-addresses;
• In S Sider - a tool for wireless networks;
• Angry IP Scanner is a system for checking free addresses that are not used for local connections.

Any network scanner of the above type operates on the same principle. This is the definition of the external IP connected device, no matter the mobile device is a device, a stationary computer or a laptop.

All applications belonging to the category of programs that are commonly referred to as "Windows 7 Scanner" use a hidden ping command, which the user does not know about. True, the external query is not performed in the form of an operation performed by Windows, but on the basis of its own development taking into account the protocol used and the DHCP server.

In this case, there may be disruptions in the proxy server connection option. You can change these settings in the network or network adapter settings, where you are prevented from using a proxy for local addresses (minimum IPv4 settings).

At the same time, mobile applications of this type are very popular. In the simplest version, we can give the following example. A person has come to a cafe and he urgently needs to write a message or send an email. He does not know the password for accessing a virtual network (or does not want to ask). If there is a corresponding application installed on the smartphone or tablet, the network scanner will work automatically, determining the nearest wireless system (or several).

Depending on the software product, there may also be the possibility of passwordless access to the network. But this is clearly illegal. Need I say that today there is a remnantly large number of so-called burglars, to which sometimes applications of this type are also included.

But no one understands that the scanner of IP-addresses of the network determines only the source through which the connection to the Internet and access to the network ( Ethernet-based network adapter , Wi-Fi-network using a router as a router) is made.

Conclusion

The worst thing is that no program of this type can scan the internal and external addresses bypassing the configuration file hosts, which stores information about calls to standard addresses. Sometimes, its contents can also have entries blocking certain resources, and accessing these settings on Windows systems has the highest priority, even with respect to DNS servers or proxies.

Therefore, installing a network scanner, it is worth considering the advisability of using such a software product. Unfortunately, applications in the form of scanners that are not controlled by Windows can cause conflicts at the system level (the work of some dynamic libraries necessary for the proper functioning of Windows, and even device drivers is blocked).

In addition, it is necessary to pay attention to the legality of penetration into a certain virtual network, not to mention the installed software, taken from unofficial (pirated) sources.