Common Network Protocols
What Is a Network Protocol?
A network protocol is a set of rules that define how data is structured, transmitted, and received over a network. These protocols act as common languages, enabling different devices to communicate and understand each other.
Why Do Security Analysts Care?
Some network protocols have vulnerabilities that attackers can exploit. For example, DNS can be manipulated to redirect users to malicious websites. Understanding protocols helps analysts mitigate these risks.
Categories of Network Protocols
| Category | What It Does | Examples |
|---|---|---|
| Communication Protocols | Control data exchange between devices | TCP, UDP, HTTP, DNS |
| Management Protocols | Monitor and manage network activity | SNMP, ICMP |
| Security Protocols | Encrypt and protect data during transfer | HTTPS, SFTP |
Common Protocols You Should Know
Communication Protocols
- TCP (Transmission Control Protocol):
- Establishes reliable connections using a three-way handshake.
- Operates at the transport layer.
- UDP (User Datagram Protocol):
- Faster but unreliable; no connection before transmission.
- Used for DNS queries; operates at the transport layer.
- HTTP (Hypertext Transfer Protocol):
- Enables client-server communication on the web.
- Uses port 80; operates at the application layer.
- Note: Insecure.
- DNS (Domain Name System):
- Maps domain names to IP addresses.
- Uses UDP (port 53) or TCP (for large responses); operates at the application layer.
Management Protocols
- SNMP (Simple Network Management Protocol):
- Monitors and manages network devices.
- Can modify device settings; operates at the application layer.
- ICMP (Internet Control Message Protocol):
- Reports errors and tests connectivity ("ping").
- Operates at the internet layer.
Security Protocols
- HTTPS (Hypertext Transfer Protocol Secure):
- Encrypted version of HTTP (via SSL/TLS).
- Uses port 443; operates at the application layer.
- SFTP (Secure File Transfer Protocol):
- Securely transfers files, often using SSH and AES encryption.
- Uses port 22; operates at the application layer.
Note: Even with encryption, source and destination IPs are not hidden from potential attackers.
Key Takeaways
- Network protocols form the backbone of digital communication.
- Security professionals must identify protocol weaknesses to protect networks.
- Mastering common protocols is essential for cybersecurity and network management.