Some of the well known ports for network communication
Here is the list of most frequently used ports for internetwork communications
21 FTP - File Transfer Protocol: used for file transfers
22 SSH - Secure SHell: used to manage remote devices on a secured channel
23 Telnet - used to manage remote devices
25 SMTP - Simple Mail Transfer Protocol: used to send emails
43 Whois - used to query database for information about domain names
53 DNS - Domain Name System: used to translate domain names into IP addresses
69 TFTP - Trivial FTP: used for file transfer to routers, switches, firewall, etc
80 HTTP - HyperText Transmission Protocol: used to share information over the World Wide Web
110 POP3 - Post Office Protocol Version3: used to retrieve emails from a mail server
123 NTP - Network Time Protocol: used to Synchronize the computer clock with a trusted time server
143 IMAP - Internet Message Access Protocol: used to access mails on a mail server
161 SNMP - Simple Network Management Protocol: a very powerful protocol to monitor and manage networked devices
162 SNMP - Simple Network Management Protocol: a very powerful protocol to monitor and manage networked devices
389 LDAP - Lightweight Directory Access Protocol: used for authentication of user account
443 HTTPS - Secure HTTP: used to share information over the world wide web on a secure channel.
465 SMTPS - Secure Simple Mail Transfer Protocol: used to send emails over a secure channel
500 ISAKMP - Internet Security Association and Key Management Protocol: used to setup VPN connections
587 SMTP - Simple Mail Transfer Protocol: used to send emails
636 LDAPS - Secure Lightweight Directory Access Protocol: used for authentication of user account over a secure channel
993 IMAPS - Secure Internet Message Access Protocol: used to access mails on a mail server on a secure channel
995 POP3S - Secure Post Office Protocol Version3: used to retrieve emails from a mail server over a secured channel
1701 L2TP - Layer 2 Tunnelling Protocol: used for VPN connections
3306 MySQL - MySQL used port 3306 to communicate with the application that requests information from the database
3389 Terminal Server - Terminal server uses port 3389 to listen for requests for remote desktop connections
3268 LDAP query - Port 3268 is used to query LDAP on organization wide objects, useful for multidomain networks
5060 SIP - Session Initiation Protocol: used for Voice Over IP
5500 VNC Server - Virtual Network Computing: used for remote desktop sharing
5800 VNC Server - Virtual Network Computing: used for remote desktop sharing
5900 VNC Server - Virtual Network Computing: used for remote desktop sharing
8080 HTTP Proxy - HTTP Proxy is a web based server which accepts your requests and forwards it on the internet thereby protecting your computer from the internet and providing web filtering.