FTP (File Transfer Protocol)
20, 21
SSH, SFTP, SCP
22
Telnet
23
SMTP (Simple Mail Transfer Protocol)
25
DNS (Domain Name System)
53
HTTP (Hypertext Transfer Protocol)
80
POP3 (Post Office Protocol version 3)
110
IMAP4 (Internet Message Access Protocol, version 4)
143
NetBIOS (Network Basic Input/Output System)
137, 138, 139
SNMP (Simple Network Management Protocol)
161
MS SQL
1433
RDP (Remote Desktop Protocol)
TCP 3389
LDAP (Lightweight Directory Access Protocol)
389
Secure LDAP (LDAPS)
636
TACACS+ (Terminal Access Controller Access Control System)
49
Kerberos
88
TFTP (Trivial File Transfer Protocol)
UDP 69
RADIUS
1812
FTPS (File Transfer Protocol Secure)
989/990
Secure POP
995
HTTPS (Hypertext Transfer Protocol Secure)
443
Secure IMAP
993
SSL/TLS
443
DHCP (Dynamic Host Configuration Protocol)
67, 68