Scanning Techniques
Types of Network Scanning
Network scanning encompasses various methodologies designed to probe and analyze network infrastructure. Understanding these techniques is crucial for effective vulnerability assessment.
1. Port Scanning Methods
graph TD
A[Port Scanning Techniques] --> B[TCP Connect Scan]
A --> C[SYN Stealth Scan]
A --> D[UDP Scan]
A --> E[XMAS Scan]
A --> F[Null Scan]
TCP Connect Scan
- Full TCP handshake connection
- Most detectable method
- Requires complete connection establishment
## TCP Connect Scan
nmap -sT 192.168.1.100
SYN Stealth Scan
- Half-open scanning technique
- Less detectable
- Faster and more subtle
## SYN Stealth Scan
sudo nmap -sS 192.168.1.100
2. Host Discovery Techniques
Technique |
Command |
Description |
ICMP Ping |
nmap -sn |
Network-wide host discovery |
ARP Scan |
nmap -sn -PR |
Local network host identification |
TCP SYN Discovery |
nmap -sn -PS |
Firewall-friendly discovery |
3. Advanced Scanning Strategies
Banner Grabbing
Retrieve service version information and potential vulnerabilities
## Service version detection
nmap -sV 192.168.1.100
OS Fingerprinting
Identify operating system characteristics
## OS Detection
sudo nmap -O 192.168.1.100
Scanning Complexity Levels
graph LR
A[Scanning Complexity] --> B[Basic Scan]
A --> C[Intermediate Scan]
A --> D[Advanced Scan]
B --> E[Port Listing]
C --> F[Service Detection]
D --> G[Comprehensive Analysis]
Best Practices
- Always obtain proper authorization
- Use minimal intrusive scanning techniques
- Respect network performance
- Document and analyze results carefully
LabEx Cybersecurity Insights
At LabEx, we emphasize practical skills in network scanning, teaching professionals how to conduct thorough yet responsible vulnerability assessments using advanced techniques and tools.
Practical Considerations
- Scan complexity depends on network architecture
- Different techniques reveal different information
- Choose scanning method based on specific objectives