Important Port Numbers

15 --- Netstat
21 --- FTP
23 --- Telnet
25 --- SMTP
42 --- WINS
53 --- DNS
67 --- Bootp
68 --- DHCP
80 --- HTTP
88 --- Kerberos
101 --- HOSTNAME
110 --- POP3
119 --- NNTP
123 --- NTP (Network time protocol)
139 --- NetBIOS
161 --- SNMP
180 --- RIS
389 --- LDAP (Lightweight Directory Access Protocol)
443 --- HTTPS (HTTP over SSL/TLS)
520 --- RIP
79 --- FINGER
37 --- Time
3389 --- Terminal services
443 --- SSL (https) (http protocol over TLS/SSL)
220 --- IMAP3
3268 --- AD Global Catalog
3269 --- AD Global Catalog over SSL
500 --- Internet Key Exchange, IKE (IPSec) (UDP 500)