Windows check if remote port is open

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Introduction

The ping command is a network tool for checking whether a remote system is up and running. In other words, the command determines if a certain IP address or a host are accessible. Ping uses a network layer protocol called Internet Control Message Protocol (ICMP) and is available on all operating systems.

On the other hand, port numbers belong to transport layer protocols, such as TCP and UDP. Port numbers help identify where an Internet or other network message is forwarded when it arrives.

In this tutorial, you will learn how to ping a port in Windows and Linux using different tools.

Prerequisites

• A Linux or Windows system
• Access to the command line
• An account with sudo/admin privileges

Can You Ping a Specific Port?

Network devices use ICMP to send error messages and information on whether communication with an IP address is successful or not. ICMP differs from transport protocols as ICMP is not used to exchange data between systems.

Ping uses ICMP packets, and ICMP does not use port numbers which means a port can’t be pinged. However, we can use ping with a similar intention – to check if a port is open or not.

Some network tools and utilities can simulate an attempt to establish a connection to a specific port and wait to see if the target host responds. If there is a response, the target port is open. If not, the target port is closed, or the host is unable to accept a connection because there is no service configured to listen for connections on that port.

You can use three tools to ping a port in Linux:

• ‎Telnet
• Netcat (nc)
• ‎Network Mapper (nmap)

See our tutorial on how to use the ping command in Linux to learn about additional ping options and variations in Linux.

Ping a Specific Port Using Telnet

Telnet is a protocol used for interactive communication with the target host via a virtual terminal connection.

1. To check whether telnet is already installed, open a terminal window and enter telnet.

2. If telnet is not installed, install it using the following command

• For CentOS/Fedora: yum -y install telnet
• For Ubuntu: sudo apt install telnet

3. To ping a port using telnet, enter the following command in the terminal:

telnet <address> <port_number>

The <address> syntax is the domain or the IP address of the host, while <port_number> is the port you want to ping.

telnet google.com 443

If the port is open, telnet establishes a connection. Otherwise, it states a failure.

4. To quit telnet, press Ctrl + ] and run the q command.

Ping a Specific Port Using Netcat

Netcat (nc) reads and writes from connections using TCP and UDP protocols. This command-line tool can perform many network operations.

1. To check if netcat is installed:

• For Debian, Ubuntu, and Mint: enter netcat -h
• For Fedora, Red Hat Enterprise Linux, and CentOS: ncat -h

2. If netcat is not installed, run the following command in the terminal:

sudo apt install netcat

3. To ping a port using netcat enter the following:

nc -vz <address> <port_number>

The output informs the user if the connection to the specified port is successful or not. If it is successful, the port is open.

Ping a Specific Port Using Nmap

Nmap is a network tool used for vulnerability scanning and network discovery. The utility is also useful for finding open ports and detecting security risks.

1. Check if you have Nmap installed by entering nmap -version in the terminal.

If Nmap is installed, the output informs the user about the app version and platform it runs on.

2. If there is no Nmap on your system, enter the following command:

• For CentOS or RHEL Linux: sudo yum install nmap
• For Ubuntu or Debian Linux: sudo apt install nmap

3. Once Nmap is installed on the system, use the following command to ping a specific port:

nmap -p <port_number> <address>

The output informs the user about the port’s state and service type, latency, and the time elapsed until the completion of the task.

4. To ping more than one port, enter nmap -p <number-range> <address>.

The <number-range> syntax is the range of port numbers you want to ping, separated by a hyphen.

For example:

nmap -p 88-93 google.com

Learn in-depth how to use nmap to scan ports with our guide How To Scan & Find All Open Ports With Nmap.

How to Ping a Specific Port in Windows?

There are two ways to ping a port in Windows:

• Telnet
• PowerShell

Ping a Port Using Telnet

Before using telnet, make sure it is activated:

1. Open the Control Panel.

2. Click Programs, and then Programs and Features.

3. Select Turn Windows features on or off.

4. Find Telnet Client and check the box. Click OK.

You activated the Telnet Client on the system.

After completing the activation, you are ready to ping a port using telnet.

Follow these steps:

1. Search for “cmd” in the start menu. Click the Command Prompt.

2. In the command prompt window, enter

telnet <address> <port_number>

The <address> syntax is the domain or the IP address of the host, while <port_number> is the port number you want to ping.

The output lets you know if the port is open and reachable. Alternatively, a connection failure message is shown.

Ping a Port Using PowerShell

PowerShell is a text-based shell that comes with Windows by default.

To ping a port using PowerShell, follow these steps:

1. Search for “PowerShell” in the start menu. Click the Windows PowerShell app.

2. In the PowerShell prompt window enter

Test-NetConnection <address> -p <port_number>

If the port is open and the connection passes, the TCP test is successful. Otherwise, a warning message appears saying the TCP connection failed.

Conclusion

Now you know how to ping and check if a port is open by using several network tools and utilities on Linux and Windows.

Bear in mind that you should not do TCP probing or scan a system unless you have the owner’s permission. Otherwise your actions may be interpreted as an attempt to compromise security.

In this how to check if port is open article, we will try to answer all the how-to questions we receive on our website.

We will add a new question from time to time base on new how to questions that users will ask.

For general question, we will try to answer it for the Windows operation system, assuming it can be asking for Windows, Linux, MAC or Mobile device.

Here is a common question regarding how to check a port is open:

• how to check 443 port open or not?
• how to check if port 443 is open?
• how to check if port 9675 is open?
• how to check port 443 is open?
• how to test port 443 is open?
• how to check if port 25 is open?
• how to check if the port 47827 open?

To check if a port is open or not on your local computer you will have to use a tool.

Using our own Open Port Viewer tool:

You can download our Open Port Viewer tool and run it (right click and run as administrator).

Open Port Viewer is an easy to use GUI tool to get the current list of used ports on your system.

In the list of ports that you will see, please check if you can see the port you are searching.

Using netstat command line tool:

Another option is to use the netstat command line tool.

To do so, please open cmd as administrator:

1. Press the Windows button
2. Type cmd
3. Right click on Command Prompt.
4. Select Run as administrator.

In the command prompt type the following:

netstat -an | find “PORT NUMBER TO FIND”

example to check for 443 with netstat:

netstat -an | find “443”

If you see the port number on the left side (red location on the blow image) the port is open.

Read more information about netstat on our netstat command article.

Using telnet command line tool:

Telnet is also a command line tool, to use it you may have to enable it first, on Windows 10.

This is how you enable telnet on windows 10:

1. Open Turn Windows Feature on or off
   1. Press the Windows Button + R
   1. On the Run dialog type: OptionalFeatures
   1. Press enter or Click OK.
2. Fin Telnet client in the list.
3. Mark V near it.
4. Press Ok

Open the command prompt as administrator (look above how to open cmd as administrator).

Type the following:

telnet localhost <PORT NUMBER>

example to check for 443 with telnet:

telnet localhost 443

If you get the following error, the port is close:

Connecting To localhost…Could not open a connection to the host, on port 443: Connect failed

Using putty tool:

To check if the port is open using putty tool, you need to download putty from the internet first.

Putty can open a terminal, like telnet or SSH to connect to a remote host, like the telnet command.

We will use it to connect a local port.

Downloading putty from putty website – Putty

When the site is open scroll down to the Alternative binary files section.

Select the 32-bit or 64-bit version of the tool, and download it to your computer.

Once it finishes downloading open it.

• Set hostname – localhost
• Set Port – The port number
• Select telnet
• Press open

Example of using putty to check port 443:

If you see the following message the port is close:

In this article, we show you 4 tools that you can use to check if port is open or not.

The above tools are designed to run on Windows operation system and you might need to be an administrator to use them.

Hope it helps.

Certain apps and processes in Windows 10 can cause problems if you’re not properly connected to the internet. Firewalls can cause these connection issues when they cannot determine whether incoming and outgoing connections pose a threat. Work around this issue and open ports for incoming and outgoing connections. We will know to check whether a TCP port is open or closed on the Windows operating system.

Basically, many times we need to check the port status when any of the below issues results in closing the port.

1. They may not be properly working.
2. External IP addresses that are in use may be set to private IPs.
3. Firewall rules may block the network.

There are several ways to check open TCP/IP ports in Windows. Here are a few options:

Using Telnet Client:

Step 1: Check whether the telnet client feature is ON or not. In order to check, open the Turn Windows feature on or off settings from the search bar. OR press the ‘window’ key and type ‘windows’ features. Then press on “Turn Windows features on or off”.

A new prompt will be opened. Search for “Telnet Client” and check the box in front of ‘telnet Client’.

Step 2: Open the command prompt. Press the ‘windows’ key and type ‘cmd’. Press “Command Prompt”.

Step 3: On the command prompt, type the command “telnet + IP address or hostname + port number” and check the status of the provided TCP port.

Step 4: If only the blinking cursor is visible, then the port is open.

Step 5: If you get the message “connection failed” then the port is closed.

Using built-in netstat command-line utility:

Step 1: Open the command prompt. 

Step 2: Run the following command:

netstat -an

Using TcpView

Another option is to use the TcpView utility from Microsoft’s Sysinternals suite of tools. This utility provides a more user-friendly interface for viewing active TCP/IP connections, along with additional information such as the process ID and process name for each connection. Steps to be followed:

Step 1: Download the TcpView utility from the Microsoft Sysinternals website. You can find the download link on the TcpView page of the Sysinternals website.

Step 2: Extract the downloaded file and run the TcpView.exe file to launch the TcpView utility. This will open the TcpView window, which shows a list of all active TCP/IP connections on your machine.

Step 3: Open the tcpview.exe (application).

By default, TcpView will display the following columns in the list of connections:

Protocol: Shows the protocol being used for the connection (TCP or UDP)

Local Address: Shows the local address and port being used for the connection

Remote Address: Shows the remote address and port being connected to

State: Shows the current state of the connection (e.g. Established, Listen, etc.)

You can use the “Local Address” and “Remote Address” columns to see which ports are being used by which applications. For example, if you see a connection with a local address of “127.0.0.1:80”, this means that the local application is using port 80 for outgoing connections.

Windows PowerShell

You can also use Windows PowerShell to check open TCP/IP ports. To do this, use the Get-NetTCPConnection cmdlet, which allows you to view a list of active TCP/IP connections and the local and remote addresses and ports being used. For example, you can run the following command to view a list of all active TCP/IP connections:

Get-NetTCPConnection | 
Select-Object LocalAddress,
LocalPort, RemoteAddress, RemotePort

Nmap

To install Nmap in the Windows command line, follow these steps:

Step 1: Download the latest version of Nmap from the Nmap website. You can find the download link on the Nmap download page: 

https://nmap.org/download.html

Step 2: Extract the downloaded file to a location on your computer. This will create a new folder containing the Nmap files.

Step 3: Open a command prompt and navigate to the directory where you extracted the Nmap files. For example, if you extracted the files to the C:nmap directory, you would run the following command:

cd C:nmap

Step 4: Once you are in the Nmap directory, you can install Nmap by running the nmap.exe file. To do this, run the following command:

nmap.exe -V

This will display the version number of Nmap, indicating that it has been installed successfully.

Step 5: To use nmap to scan for open TCP/IP ports, run the “nmap -sT” command, followed by the IP address or hostname of the machine you want to scan.

nmap -sT localhost

This will scan the specified host or IP address and display the results. You can also use the -h option to view a list of available options and arguments for the nmap command. Overall, installing Nmap in the Windows command line is a straightforward process. You can download the latest version of Nmap from the Nmap website, extract the files, and then run the nmap.exe file to install it. Once it is installed, you can use the nmap command to scan hosts and IP addresses and view the results.