In this post, we will discuss how you can use various tools to send a ping request to check if a target port on a specific host is alive.
Ping is one of the most fundamental tools when it comes to network troubleshooting. It allows you to quickly test whether a given service/port is responding or not. Due the lightweight nature of ICMP packets, it allows ping to quickly fetch useful information about a given system without sending a series of packets that would otherwise overwhelm the host (in some cases).
Although pinging an entire host can be useful for checking if a given host is up, it does not offer much information about if a target port is up.
Method 1 - Use Telnet
You are probably familiar with
telnet. Also known as Terminal or Network, Telnet is a command-line utility that allows you perform interactive network communication using the TELNET protocol.
An telnet tutorial is coming up soo. Stay tuned for that.
To ping a specific port using telnet, use the command syntax as:
telnet [ip_address] [port_number]
The telnet command is available in both Windows and Unix systems. However, you may need to enable Telnet in Windows.
To learn how do that, check the link below:
On macOS, use
brew to install Telnet:
brew install telnet
On Debian and Debian-Based distributions, install telnet:
sudo apt-get install telnet
The example below shows how to use telnet to check if Nginx Server is running.
telnet 184.108.40.206 80
If the service is running, telnet will connect and return an output as:
Trying 220.127.116.11... Connected to 18.104.22.168. Escape character is '^]'.
To close the connection, press
CTRL + C]
Method 2 - Using Nmap
Nmap is another 'crazy' networking tool that every sys admin and security researcher should use. We will be putting out nmap tutorials in a near future. Make sure to subscribe to get notified when we do.
Start by installing nmap:
sudo apt-get install nmap
brew install nmap
sudo yum install nmap
Once installed, check if a port is up by running the command:
nmap -p <port> [target_address]
sudo nmap -p 80 22.214.171.124
Nmap will return detailed information including the latency, port number, associated service and its state. An exmaple output is as shown:
Starting Nmap 7.93 ( https://nmap.org ) at 2022-10-02 10:49 EAT Nmap scan report for 126.96.36.199 Host is up (0.28s latency). PORT STATE SERVICE 80/tcp open http Nmap done: 1 IP address (1 host up) scanned in 0.65 seconds
Method 3 - Using Netcat
Netcat is another tool you can use to check if a port is up. Check the nectat cheat sheet to learn more.
To ping a port using netcat, run the command:
nc -vz [target_address] [port_number]
sudo nc -zv 188.8.131.52 80 Connection to 184.108.40.206 port 80 [tcp/http] succeeded!
We can see that the connection to the target address and port is successful. This indicates the port/service is up.
Method 3 - Using cURL
We obviously cannot forget to mention cURL in this list. The command syntax is as shown:
curl -s [host:port]
curl -s 220.127.116.11:80 >/dev/null && echo Connected. || echo Failed.
The command should "Connected" if the port/service is up.
Method 4 - Using Windows PowerShell
In Windows, you can use the
Test-NetConnection cmdlet to test if a port is up and running. The command syntax is as shown:
Test-NetConnection [ip_address] -p [port_number]
Test-NetConnection 18.104.22.168 -p 80
The command should return details about the target host and the connection status.
ComputerName : 22.214.171.124 RemoteAddress : 126.96.36.199 RemotePort : 80 InterfaceAlias : Ethernet SourceAddress : 192.168.1.101 TcpTestSucceeded : True
Method 5 - Using PsPing Utility
In Windows, you can also use the PsPing utility which is part of Windows SysInternals tools. Download the tool in the resource below:
You can then use the command synax below to ping a specific port:
The command should send ping request to the target address and port and return the output as shown:
PsPing v2.10 - PsPing - ping, latency, bandwidth measurement utility Copyright (C) 2012-2016 Mark Russinovich Sysinternals - www.sysinternals.com TCP connect to 188.8.131.52:80: 5 iterations (warmup 1) ping test: Connecting to 184.108.40.206:80 (warmup): from 192.168.1.101:59835: 239.30ms Connecting to 220.127.116.11:80: from 192.168.1.101:59837: 239.56ms Connecting to 18.104.22.168:80: from 192.168.1.101:59838: 239.36ms Connecting to 22.214.171.124:80: from 192.168.1.101:59839: 237.90ms Connecting to 126.96.36.199:80: from 192.168.1.101:59842: 237.86ms TCP connect statistics for 188.8.131.52:80: Sent = 4, Received = 4, Lost = 0 (0% loss), Minimum = 237.86ms, Maximum = 239.56ms, Average = 238.67ms
The above port is up.
In this post, we explored various methods and tools you can use to ping a specific port in both Windows and Unix based systems.
Thanks for reading and catch you in the next one!!