Use Telnet to Check Open Ports with video

Use Telnet to Check Open Ports 

 

Many times we need the details the open ports of any device and that time we download Port scan softare.Which is very delirious and velnerble.

You can check if a port is open on a device by issuing the telnet command. If it is open, you will see a blank screen after issuing the command:

 

Please check and enable the telnet client  setting in the windows feature.

 

Note, in Windows Vista and Windows 7 you may need to enable telnet first:

• Go to Start -> Control Panel -> Programs

• Under Programs and features, click Turn Windows features on or off

• Check the box for Telnet Client

• Click OK

 

 

Telnet [ ip] [port]

• [domainname or ip] is the domain name or IP address of the server to which you are trying to connect

• [port] is the port number where the server is listening

If the port is open, you will see a blank screen. This means that the connection is successful. If the port is closed, you will receive a Connect failed message.

For example, if I wanted to test whether the device 192.168.1.100 had it’s webserver (port 80) running: 

telnet 192.168.1.100 80

 

 2- port 80 is open on this device.

 

 

Now, let’s see if the device is listening for Modbus TCP connections (port 502):

  

Here we see the Connect failed message which tells us this device is NOT open on port 502.

 

 

You can also watch this video in hindi......