Nmap

Nmap (Network Mapper) is an open-source tool widely used for network discovery and security auditing. Nmap is primarily used for port scanning and network exploration, helping to identify running services and operating systems on a network, and detecting security vulnerabilities.

Here’s a detailed summary of the Nmap commands you mentioned, along with their descriptions:

1. TCP SYN Scan

nmap -sS 192.168.0.1

• Description: This scan uses SYN-ACK packets to quickly check for open ports. It's a stealthy scan, as it doesn't complete the TCP handshake, making it less likely to be detected by firewalls or intrusion detection systems.

• Use Case: Best for fast port scanning when you want to avoid detection and you are not concerned about getting full details on the services.

---

2. TCP Connect Scan

nmap -sT 192.168.0.1

• Description: The TCP Connect Scan completes the full TCP handshake (SYN, SYN-ACK, ACK), making it more reliable and accurate but slower than the SYN scan.

• Use Case: Useful when you don’t mind detection and need detailed and accurate information about the target system.

---

3. UDP Scan

nmap -sU 192.168.0.1

• Description: Scans UDP ports instead of TCP. Unlike TCP, UDP doesn't establish a connection, so the scanning process is a bit different.

• Use Case: Required for detecting services running over UDP, like DNS or DHCP, which often run over UDP.

---

4. Port Specification

nmap -p 1-100 192.168.0.1

• Description: This command scans specific ports or a range of ports. In this case, it scans ports 1 through 100 on the target.

• Use Case: When you want to target specific ports, either a small range or just a single port.

---

5. Aggressive Scan

nmap -A 192.168.0.1

• Description: This scan uses several advanced features, including OS detection, service version detection, script scanning, and traceroute. It’s comprehensive but may be more intrusive and slow.

• Use Case: Use when you need detailed information about the target, including OS type, service versions, and vulnerabilities.

---

6. OS Detection

nmap -O 192.168.0.1

• Description: This command tries to detect the operating system running on the target system by analyzing network behavior and response patterns.

• Use Case: Use it when you need to know the operating system of the target to tailor your attack or defensive strategy.

---

7. Version Detection

nmap -sV 192.168.0.1

• Description: This scan identifies the versions of the services running on open ports by sending probes to each service and matching responses to a signature database.

• Use Case: Useful for finding out the exact versions of services, which helps in vulnerability assessment.

---

8. Verbose Output

nmap -v 192.168.0.1

• Description: The -v flag makes Nmap provide more detailed output, showing progress and real-time status during the scan.

• Use Case: Use when you want more information about the scanning process and its progress.

---

9. Input from List

nmap -iL targets.txt

• Description: This option allows you to specify a list of targets (from a text file) to scan. It's used for bulk scanning.

• Use Case: Use this when you have a large number of targets to scan and prefer to store them in a list file rather than typing them manually.

---

10. Timing Template

nmap -T <0-5> 192.168.0.1

• Description: The -T option allows you to control the speed of your scan. The values range from 0 (slowest) to 5 (fastest). Faster scans may be detected more easily and may overload the target.

• Use Case: Use when you need to adjust the scan speed based on performance or stealth requirements.

---

Summary

Each of these Nmap commands is tailored for specific tasks, whether you're conducting a fast scan, checking service versions, or performing a detailed security audit.