Most Internet-based applications, such as websites, communicate using a TCP/IP endpoint - that is, an IP address and port number.
If a remote computer cannot connect to your application or website's port number, it will be unable to use it.
Ports can be blocked using hardware- or software-based firewalls, which can restrict access conditionally based on the IP address or machine that is trying to connect.
Use the Open Port Checker tool on Solid Tools for Developers to:
Enter a hostname, IPv4 or IPv6 address in the "Hostname or IP address" field.
To connect to a server if you don't know its IP address, enter its hostname (e.g. www.google.com) and select whether to use an IPv4 or IPv6 connection. If you select IPv6, the hostname must have an IPv6 (AAAA) DNS record.
To connect to a server using its IPv4 address, enter the IP address and ensure the IPv4 option is selected.
To connect to a server using its IPv6 address, enter the IP address and ensure the IPv6 option is selected.
Select one of the common TCP/IP port numbers from the list, or enter your own port number to connect to.
A successful connection will be displayed in green. This means the Solid Tools for Developers was successfully able to connect to the port - the port is open.
A failed connection will be displayed in red. This means the Solid Tools for Developers was unable to connect to the port - the port is either blocked or the application is not listening.