| FTP – File Transfer Protocol
tcp 20 (active mode data), tcp 21 (control) | Transfers files between systems |
| SSH - Secure Shell
- tcp 22 | Encrypted communication link
• Looks and acts the same as Telnet |
| Telnet - tcp 23 | Insecure console access
• Login to devices remotely
• Not the best choice for production systems |
| Simple Mail Transfer Protocol SMTP tcp 25 | Used to send email from clients to servers, and for transferring email between servers. It never is used by clients to receive emails from servers |
| DNS - Domain Name System UDP 53 | Converts names to IP addresses |
| HTTP tcp 80 | Hypertext Transfer Protocol
• Communication in the browser
• And by other applications |
| HTTPS tcp 443 | Connections are encrypted using either Secure Socket Layer SSL or Transport Layer Security
TLS protocols |
| Internet Message Access Protocol v4 tcp 143 | Used by clients to receive email from servers; never used to send email
• Includes management of email inbox
from multiple clients |
| RDP - Remote Desktop Protocol
TCP port 3389 | Microsoft's proprietary remote access protocol |
| NetBIOS name service
UDP 137 | Register, remove, and find Windows services by name |
| NetBIOS datagram service
UDP 138 | Windows connectionless data transfer |
| NetBIOS session service
TCP 139 | Windows connection-oriented data transfer |
| SMB tcp 445 Server Message Block | Windows file transfers and printer sharing |
| TCP 548 | Apple Filing Protocol
Mac OS file transfers |
| tcp 427, udp 427 | Service Location Protocol SLP
Find Mac OS services by name |
| udp 67, udp 68 | Dynamic Host Configuration Protocol DHCP |
| tcp 389 | Lightweight Directory Access Protocol LDAP |
| UDP 161 | Simple Network Management Protocol SNMP |
