What is a TCP Check? March 03, 2025 19:55 Common questions:Does my domain resolve over this port?How do I check connectivity over a specific port?How TCP checks work:Attempts to open a TCP connection on the specified port. You can test if the port is available over TCP by running telnet in the terminal by typing telnet followed by the IP and then the port number:# telnet # telnet 192.168.1.1 23If you are able to connect and it does not timeout, then our monitoring systems will pass it in a TCP check.