Important Port Numbers:

HTTP ---------- 80

FTP ------------ 20,21

TelNet ---------- 23

SMTP ---------- 25

DNS ----------- 53

TFTP ----------- 69

SNMP ---------- 161

RIP ------------- 520

IMAP 4--------- 143

IMAP 3 --------- 220

RPC ------------ 135

LDAP ---------- 389

Net Stat -------- 15

WINS ---------- 42

BootP ---------- 67

DHCP ---------- 68

POP2 ---------- 109

POP3 ---------- 110

Net BIOS ------ 139

SSL(HTTPS) --- 443

SQL Server ---- 1433

NFS ------------ 2049

SSH ------------ 22

RAP ----------- 38

BGP ----------- 179