Network Port

Simple definition

An IP address is the machine and port is the service to be contacted on this machine.

Technical definition

TCP and UDP The known ports include 53 ports for the port of use, which are not included in the list of ports. DNS80 for HTTP443 for HTTPS and 25 or 587 for SMTP.

What is it used for ?

Operate multiple services on a single server and create rules for firewall precise.

Practical example

The browser contacts the server’s IP address on the port TCP 443 to open a site HTTPS.

Common issues

Closed or filtered port
Service not listening on the expected port
Conflict between two applications
Redirection NAT incorrect

TCP · UDP · Firewall · NAT · IP address

Key takeaway: This entry explains the general operation of the term. Exact settings may vary depending on software, vendors and environments.