FTP data port (Active Mode)

FTP control port

SSH

SCP (uses SSH)

SFTP (uses SSH)

Telnet

SMTP

TACACS+

DNS name queries

DNS zone transfer

TFTP

HTTP

Kerberos

POP3

SNMP

SNMP trap

NetBIOS (TCP rarely used)

NetBIOS

NetBIOS

IMAP4

LDAP

HTTPS

SMTP SSL/TLS

IPSec (for VPN with IKE)

LDAP/SSL

LDAP/TLS

IMAP SSL/TLS

POP SSL/TLS

L2PT

PPTP

RDP

Microsoft SQL Server