Host discovery and enumeration is the foundation of every network penetration test. Rather than targeting a single protocol, this phase identifies live systems, their operating systems, and running services across a target network. Tools like Nmap, Masscan, and Netdiscover map the attack surface before service-specific testing begins.
Thorough host enumeration prevents blind spots. Missed hosts mean missed vulnerabilities. Attackers and testers alike start by determining which IP addresses are alive, what ports are open, and what services respond. ARP scanning works on local segments, ICMP and TCP probes reach across routed networks, and DNS enumeration reveals hostnames and naming conventions that hint at function and importance.
Standard techniques include ARP scans (arp-scan -l), ICMP sweeps (nmap -sn), TCP SYN scans (nmap -sS), and full port scans to catch services on non-standard ports. OS detection (nmap -O) and service version detection (nmap -sV) add context. Combining results from multiple scanning methods ensures complete coverage, since firewalls and filtering may hide hosts from any single technique.
Reconnaissance
Guides for mapping hosts via passive OSINT, network sweeps, and active prob
Network Mapping
Passive Reconnaissance
Discover exposed host information using passive techniques—DNS enumeration, WHOIS lookups, and OSINT tools—without directly interacting with the target infrastructure.
Enumeration
Guides on host discovery, port scanning, OS fingerprinting, and NSE scans
ICMP Host Discovery and Ping Sweeps
Nmap Service Enumeration (NSE)
OS Fingerprinting and Banner Grabbing
Port Scanning with Nmap
Discover live hosts, open ports, and running services using Nmap's scan techniques, flags, and output formats for effective network enumeration.
Vulnerability Discovery
Guides for scanning hosts to find CVEs and misconfigs with Nmap NSE
Nmap Vulnerability Scanning (NSE)
Data Exfiltration
Exfiltrate data via ICMP when TCP and UDP egress is blocked