Use the netstat command lists all the active ports. Port number is usually used for web servers. When a port number is added to the end of the domain name, it drives traffic to the web server.
However, users can not reserve port for secondary web servers. In the Run dialog box, enter: cmd. Click OK. In the command window, enter: netstat -ano. A list of active connections is displayed. Start Windows Task Manager and select the Processes tab. In the left pane, click Inbound Rules. Portqry used to be the command of choice for checking remote ports being alive and listening but it was only available up till Windows XP and Windows Server If you are going strictly with a DOS based command then you are left with no option but to install telnet in Windows To install Telnet, follow the instructions below:.
Where google. You can also put an IP address instead of the name. You should replace 80 with you desired port number. If the PortQry command string does not include -l , PortQry ignores -y.
When you query over slow or unreliable network links, the normal wait time may be too short to receive a response. By default, when you use -n to specify an IP address for the target computer, PortQry does a reverse name lookup to resolve the IP address to a name.
This process may be time-consuming, especially if PortQry can't resolve the IP address. Use -nr to skip this step of the query. If you use -n to specify a computer or domain name, PortQry ignores -nr. PortQry can't use a port that another process is already using. If the port that you specify is already in use, PortQry returns the following error message: Cannot use specified source port. Port is already in use. Specify a port that is not in use and run the command again.
When this occurs, PortQry records "Using ephemeral source port" in its output. To temporarily turn off the IPSec policy agent so that you can use port , run net stop PolicyAgent. When you have finished testing, run net start PolicyAgent. You must delimit this value by using exclamation points, as shown in the left column. The default community name is public. When you use -q , PortQry suppresses all screen output except for error messages.
To see output other than error messages, use -q together with -l. PortQry records the normal output in the log file. If a log file already exists and you use -q together with -l , PortQry overwrites the existing log file without prompting you.
You cannot use -q together with -o , -r , or -p both. This parameter is especially helpful when you use a batch file to run a PortQry command string. This output is similar to the output that the netstat. On computers that support PID-to-port mappings, the output includes the PID of the process that's using the port on the local computer. If you use the verbose option -v , the output also includes the names of the services that the PID belongs to and lists all the modules that the process has loaded.
You can use this information to determine which ports are associated with a particular program or service that's running on the computer. Monitor a specific port for changes. To stop monitoring, press Esc. Monitor a specific PID for changes in the number and state of connections. You cannot use -wt by itself or together with -local. Queries the current destination, using the current settings.
The default protocol is tcp. However, the output returned when you use these commands might not resemble the output of the netstat tool. For more information about both commands, see the lsof and ss command manuals.
The following example shows the output for three common programs that are listening on three different sockets. If the list of listening daemons is long, you can use grep to filter it. For example, to filter out everything except the default web server port 80 , run the following command:. Note : A super-server, such as xinetd, might be listening on the port.
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