nmap

• Network mapping tool
• It works by sending various network messages to the IP addresses in the subnet
• nmap commands need to run as root user or with sudo

# List of active IP addresses
nmap -sn "192.168.1.0/24"

# Detailed summary
nmap "192.168.1.0/24"

# Aggressive scan
nmap -A -T4 "192.168.1.11"