Ports allow network and internet-connected devices to interact using specified channels. While servers with dedicated IP addresses can connect directly to the internet and make ports publicly available, a system behind a router on a local network may not be open to the rest of the web. To overcome the issue, port forwarding can be used to make these devices publicly accessible.
Networked services and apps running on various devices make use of ports at specific numbers as a means to initiate connections and establish communications. Different ports can be used simultaneously to separate and parse different types of traffic or requests easily. Ports are generally associated with specific services, such that a client can connect to a server on a particular port and assume that the server will accept a connection at that port and respond appropriately.
Some commonly used ports are shown below.
21: FTP (File Transfer Protocol)
22: SSH (Secure Shell)
23: Telnet (Teletype Network)
25: SMTP (Simple Mail Transfer Protocol)
80 : HTTP (Hypertext Transfer Protocol)
194: IRC (Internet Relay Chat)
443: HTTPS (HTTP Secure)
If you are viewing this guide on the internet and using a web browser, you're probably connected using HTTPS, which operates over port 443.
While ports make it simple to identify and address specific requests, port-numbering conventions are a standard, not a rule. Ports can be used for whatever a person may choose to host on them, so long as the connection between the client and server on a given port uses a consistent protocol.
In web browsers, non-standard HTTP ports can be specified following a colon at the end of an IP address or URL to attempt to load HTTP content over that port. If a web server is running on a local machine on port 8080 rather than ..
Support the originator by clicking the read the rest link below.
