A simple tools that check the given host if is up or down in a specified port or service (available : http(s), SMTP ,DNS ).
The Host Health tool is IP address based service, domain values are translated to their pointing IP address(es) as provied by DNS service.
please read the term of use above carrefully before using this tools.
During a network communication, the different computers and devices exchange information that is generally intended for a separate application (the mail client or the internet browser for example).This information passes through the same IP address most of the time. It is necessary to know to which application this information is intended. This is where the notion of computer port comes in.A port is a unique number encoded on 16 bits. There are therefore 65536 different ports possible.
A network communication protocol is an agreement that specifies a common language two devices will use to exchange messages. The term derives from diplomatic vocabulary, in which a protocol specifies the rules under which a diplomatic exchange occurs.