## Common Protocols & Ports

Memorize these.

| Port | Protocol | Service | Secure? |
|---|---|---|---|
| **20/21** | FTP | File Transfer | No (Cleartext) |
| **22** | SSH | Secure Shell (Remote Linux) | **Yes** |
| **23** | Telnet | Telemetry (Remote CLI) | No (Cleartext) |
| **25** | SMTP | Email Sending | No (Use 587) |
| **53** | DNS | Domain Name System | No (DNSSEC exists) |
| **80** | HTTP | Web Traffic | No |
| **443** | HTTPS | Encrypted Web Traffic | **Yes** (TLS) |
| **110** | POP3 | Email Retrieval | No |
| **143** | IMAP | Email Retrieval | No |
| **3389** | RDP | Remote Desktop (Windows) | Yes |
| **445** | SMB | Windows File Share | No (v1/v2 vulnerable) |

### Traffic Analysis
*   **Cleartext** protocols (HTTP, Telnet, FTP) show passwords in Wireshark.
*   **Encrypted** protocols (HTTPS, SSH) show garbage characters.