Data exchange between nodes in network network protocols (logical interfaces) of different level manage. The transport protocol of TCP establishes connection between a node client and a node server and controls reliability of transfer of data packets. Data exchange happens between applications which are installed on computers. The network port is a conditional concept, number which is assigned to the application that the transport protocol knew where to address packages. Number it lies in the range from 1 up to 65535.
Instruction
1. That data exchange happened successfully, it is necessary that the relevant ports in nodes were open, i.e. could accept and transfer data. Process of search of open ports is called scanning. Both hackers, and system administrators are engaged in it: the first – to implement malicious software on someone else's computer, the second – to prevent the first to make it. You can check ports, having installed on the computer the special program – the scan of ports or by means of on-line scanners. Visit the website WindowsFAQ.ru: http://www.windowsfaq.ru/content/view/451/82/.
2. If on your computer the firewall with the detector of the attacks and automatic blocking of the attacking node is installed, disconnect this option or add WindowsFAQ.ru to the list of exceptions, otherwise the scanner will be blocked. In the section "Scanning Settings" enter numbers of the first and final ports from that range which you want to check. It can be the so-called backed-up numbers – from 1 to 1023, or all ports on your computer.
3. It is important correct to install time during which the scanner will expect the answer from port. If "The connection timeout" (this parameter so is called) to make too small, the port can not manage to answer and will be mistakenly defined as closed. On the other hand, too big wait time will significantly slow down check. It is better to accept the recommended value – 0.3 sec.
4. "The host address" and "Host name" - your IP address which service automatically determines. If the address is not defined, scanning will not begin. Click "OK" for scanning start. After that the new window in which the process course is displayed will open.
5. After completion of search the result will be displayed: - date and time of check;
- host address;
- numbers of the checked ports;
- the number of the opened and closed ports;
- scanning duration. Besides, service will make recommendations how to define process which uses open ports.
6. You can start scanning from the computer. Download the V2.1 Port Scanner program of http://www.softportal.com/software-4285-skaner-portov.html.
7. In the section "Scan Ports" enter into windows initial and final port numbers from that range which you will check. If the computer not in network, it is not necessary to enter its IP address. Set scanning speed in appropriate section. It is defined by answering interval of port. It is better to select average rate, on the one hand, to avoid errors in determination of the status of port, and with another – not too to drag out verification process. Note a checkbox the Display Data on Port point to see search result. The scanner finds open ports and defines processes which use them.