Knowledgebase: Dedicated Servers
DNS Lookup
Posted by Muslim KHAN on 26 September 2016 05:15 AM

Every computer which accesses the internet or is connected to a network uses ports to communicate. Ports are almost like individual conversations going on over the same telephone line but which each port talking about a different thing. For example, every time you access a website using http, the chances are you’ll be using port 80. For other protocols such as ftp (file transfer) different ports are used, in this case port 21. Email, secure connections, streaming etc. all use different ports which helps control the flow of data and filter desired information from undesired.

Now for many people, you never see or need to know that your computer is doing this automatically. However in some special cases, a program wants to use an unusual port number and if you have a firewall installed, it may be set to block the port, preventing the program from communicating. You may get pop-up windows telling you about the request but you may not so if a program tries to communicate across a network or the internet and  fails, it could be worth trying it without your firewall turned on to see if that is the problem. If it is, you can set up rules to allow that program access.

Some of the important ports are given below:

21 => FTP (File Transfer Protocol)
22 => SSH
23 => Telnet
25 => SMTP (Outgoing Mail Server)
43 => WHOIS service
53 => name server (DNS)
80 => HTTP (Web server)
110 => POP protocol (for email)
995 => POP over SSL/TLS

143 => IMAP Protocol (for email)
993 => IMAP Secure
443 => HTTP Secure (SSL for https:// )

3306 = > MysQL Server

2082 => CPANEL
2083 => CPANEL - Secure/SSL
2086 => CPANEL WHM
2087 => CPANEL WHM - Secure/SSL
2095 => cpanel webmail
2096 => cpanel webmail - secure/SSL

Command Matrix => 7500
Plesk Control Panel => 8443
DirectAdmin Control Panel => 2222
Webmin Control Panel => 10000