Common Ports

The following ports are common to most servers.

FTP - 21 
SSH - 22 
Telnet - 23 
SMTP - 25 
DNS - 53 
HTTP - 80 
POP3 - 110 
IMAP - 143 
HTTPS - 443 
MSSQL - 1433 
MySQL - 3306 
Remote Desktop - 3389 
PostgreSQL - 5432 
VNC Web - 5800 
VNC Client - 5900 
Urchin - 9999 or 10000