Important Port Numbers

Here is a list of important port numbers categorized by the type of use

Databases
3306	MySQL
1433	MS SQL Server
5432	PostgreSQL
Remote Access - Graphical
3389	MS Remote Desktop
5800	VNC-HTTP
5900	VNC
Remote Access - Console
22	SSH
23	Telnet
512	Rexec
513	Rlogin
514	RSH
Remote Data Transfer & Management
20	FTP Data
21	FTP
69	TFTP
2049	NFS
Directory Service
389	LDAP
636	LDAP Secure
Web
80	HTTP
443	HTTPS
3128	Squid Web Proxy
Mail & Chat
25	SMTP
110	POP3
995	POP3S
143	IMAP
993	IMAPS
5222	Jabber
5223	Jabber SSL
Infrastructure Management
53	DNS
1512	WINS
67	DHCP Server
68	DHCP Client
123/UDP	NTP
161	SNMP