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Port check tool

Working with web servers and web hostings the webmaster must know how to check a particular port for availability. This requires using additional tools. The ping command is typically used for basic server reachability testing. But this utility works with ICMP packets. So it is impossible to check access for a specific port with it. Or the web resource may block the response to ICMP packets for security reasons.

Open port check basics

Every device and website on the Internet has its own IP address. But a single server can run multiple network applications at the same time. For example, there is an Internet server with an IP address. It contains: web server, mail server, FTP server. How can we make sure that we can contact the mail server? This is what a port is for. And if you check port status, you will be able to identify network applications accessibility and overall server availability.

In more simple terms, when you try to test port, you are sending a request just the same as the ping command, only scanning the particular port access. And, as it was mentioned, when you try to check port, you can also check an API or software using this port. So basically when a port check tool is used to scan a port and it sends a request, this software answers to a tool with a response. And it allows not only to test accessibility, but also response speed and other metrics, depending on a used tool.

Effective ways how to check if a port is open

One of the most obvious ways for experienced webmasters to check the port of a particular server is to use the telnet network command. But today the tool for scanning ports is available only in Terminal on Linux systems, and is not available on Windows by default. To use a telnet scanner to check ports, this component must be installed additionally.

Another method to test port of a server or other web resource is through specialized software or, which is much more convenient, through online services. And on the Internet you can easily find a useful tool to find and test a particular web server port for availability. For example, port check tool on Host Tracker website monitoring platform.

Such service allows to test port connection stability and accessibility, providing a lot of useful info to users. With it you will be able to access the port and to understand whether the ports are open or not, and find a cause of inaccessibility of a web resource related to this port.

Why it is important to check port open status

The purpose of port open check and network scanning is to determine the organization of a system of IP addresses, host points, and various ports in order to properly locate open or vulnerable servers and the level of security. Both network and check open port procedure reveals whether there is a security service, such as a firewall, between the web server and the user's hardware.

Port availability scans are also needed to identify open ports on the network that allow unauthorized access. It is important to note that both IT administrators and cybercriminals can use network and open port check tool to check security policies, identify vulnerabilities, and exploit potential weaknesses in order to gain access to a web resource.

Open ports indicate that the target website, server or network is actively accepting connections or datagrams and sending packets back, confirming that they are waiting for data transmission. It also indicates that they are using the service used for check my port scanning(usually TCP or UDP).

Various ways to check if a port is open or blocked is usually the main target of a scan, as hackers can use them to attack. The task of IT administrators, in turn, is to try to block opened ports using firewall software or system rules to secure them without restricting access to legitimate users.

The port number, combined with the IP address, forms important information that is stored by each ISP to fulfill requests. Ports from 0 to 1023 are widely known. They are designed to use the Internet through a computer or any other device, although they can perform specialized tasks as well. They are managed by the Internet Assigned Numbers Authority (IANA). It is also important to know the following ports, which are in constant use:

  • 20 (UDP) supports the file transfer protocol (FTP) used to transfer data.
  • 22 (TCP) supports the Secure Shell Protocol (SSH) for secure login, data transfer, and port forwarding.
  • 53 (UDP) is reserved to the Domain Name System (DNS), to transform domain names to IP addresses and back.
  • 80 (TCP) is reserved to the Hypertext Transfer Protocol (HTTP) for Internet services.

Ports 1024 to 49151 are marked as "registered", which means that those ports are reserved by various software corporations. And 49151 through 65536 are dynamic and private ports which can be used by almost anyone.