One of the little things you can do to improve the security of your computer is to check which connections are open and how network bandwidth is used . In particular, it is important to check programs that attempt to communicate on the Internet or other internal networks.
From any computer (Windows, Linux or Unix) you can check any open TCP and UDP connection by running the netstat command from the DOS command prompt.
Netstat shows network statistics and displays all incoming and outgoing connections from the computer.
The most interesting information is related to ip addresses and ports .
The port is represented by a fixed but different number for each program that connects to the network.
To understand what it means just think of a street in the city as an IP address and the house number of each building is the door of a program .
IP address + port number make up the socket, that is the complete address.
To read all the open connections on the computer you can use some programs that greatly simplify this diagnostic operation.
Understanding if and how programs and applications use the network and exchange data over the internet is important for identifying viruses and for configuring any routers or firewalls.
1) Moo0 ConnectionWatcher is a simple program, which looks like a ttask manager, which allows you to view any TCP / UDP connection made to and from your computer.
It lets you know which applications are connected to the network and the number of bytes transferred.
Basically, Moo0 ConnectionWatcher is like a graphical and more user friendly version to use the Netstat command.
Moo0 ConnectionWatcher displays the following information: the protocol (TCP or UDP), the connection status (if active or listening), the process ID, the name of the process or program, the local port, the remote port, name remote host, the duration of the connection, the total number of bytes exchanged and the connection speed.
The network usage statistics are in real time, therefore they are automatically updated with a frequency that can be set manually from the View menu.
By right clicking on an item in the list, a menu opens from which you can disconnect a program, close it or open its path to locate it on your computer.
Although the netstat command is much more powerful and can provide more detailed information, Moo0 ConnectionWatcher is a tool within the reach of the less experienced.
2) You can also use another free tool, called CurrPorts, to view a list of all the TCP / IP and UDP ports currently open on the local computer.
It is a portable program and does not need to be installed and, to use it, just extract the downloaded .zip file and run cports.exe.
For each port that lists CurrPorts, information about the process that opened the port will be displayed.
These can be selected and closed, or the information of a door can be copied to the clipboard or saved in an HTML, XML or csv text file.
To sort the list of a specific column, just click on the column header.
CurrPorts works with Windows NT, Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista and Windows 7 and there is a separate download of CurrPorts for 64-bit versions of Windows.
3) NetStalker is an enhanced version of CurrPorts, which allows you to view all network activity on your computer in real time.
Every time a new program is seen that uses the internet connection, it displays a message to decide whether to authorize it or not.
4) A third program to monitor the ports in use and the TCP and UDP connections is PortExpert .
PortExpert displays all applications and programs connected to remote addresses, such as the browser or e-mail client.
You can run a whois check on the remote address to find out who it is, to open the address in the browser or to open the process folder.
5) TinyWall to protect programs' internet access using the Windows internal firewall .
6) Glasswire which monitors and protects the computer's internet connection
Using a tool like these serves three main reasons :
1) If the internet goes slower than usual, the fault could be a program or, worse, a virus, which consumes bandwidth.
2) If you connect to the internet via a router and a program that is supposed to work online refuses the connection, you may need to open the door of this application on the router.
With the connection verification tool you can easily read which is this port.
3) If you have installed a firewall and wanted to create precise and more stringent rules, you can see all the information you need: port and IP address.
4) Seeing the programs that connect can become useful for balancing the use of internet bandwidth and managing connection priorities.
Another program to see which programs connect to the internet is TCPEye which was discussed in another article.
Very important, to monitor the network bandwidth and internet traffic is the tool for Windows Networx that manages to extract all the main information to know who the computer is communicating with.
Finally, I remember the list of programs to solve network and internet connection problems.
