Question: What are some common port numbers used in web hosting?
Answer: Most firewalls come configured with the essential port numbers open and the rest of them closed. Nevertheless, it is still important to know which ports do what, whether you are running a dedicated server or just one shared hosting website.
80 – Arguably the most essential port, it is the standard HTTP port on nearly all web servers, unless changed. It is the default port for Apache.
443 – This is the standard port for HTTPS. SSL encrypted sites will use this.
25 – SMTP uses this port for mail transport. Most mail servers, including Sendmail and Postfix use this by default. Some ISPs block port 25, so if you are unable to use your hosting account to send mail, this may be the cause.
110 – The standard port for POP3 incoming mail servers.
143 – The standard port for IMAP incoming mail servers.
3306 – The default port for MySQL databases. Unless you access databases using remote software, you can keep this port closed on your firewall.
21 – The standard port for FTP.
22 – The standard port for SSH
There are numerous other ports that might be of interest to you, depending on your setup. Read your web host’s knowledge base and your firewall’s documentation for more information.
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