nmap

This uses the nmap tool to perform a detailed TCP port scan on the IP range 192.168.0.0/24.

sudo nmap -sS -p- -PE -PP -PS80,443 -PA3389 -PU40125 -A -T4 -oA tcpscan-%D 192.168.0.0/24 

• sudo: Runs the command with administrative privileges.

• nmap: The command-line tool used for network exploration and security auditing.

• -sS: Performs a TCP SYN scan, which is the default scan type for privileged users.

• -p-: Scans all 65,535 TCP ports.

• -PE: Sends ICMP echo requests (ping) to discover live hosts.

• -PP: Sends ICMP timestamp requests to discover live hosts.

• -PS80,443: Sends TCP SYN packets to ports 80 and 443 (default web server) to discover open ports.

• -PA3389: Sends TCP ACK packets to port 3389 (default RDP) to discover open ports.

• -PU40125: Sends UDP packets to port 40125 (unlikely to be in use) to discover open ports (some services such as the chargen protocol respond to empty UDP packets).

• -A: Enables aggressive scanning options, including OS detection, version detection, script scanning, and traceroute.

• -T4: Sets the timing template to "Aggressive" to speed up the scan (otherwise it can take quite a while, even on a /24 network).

• -oA tcpscan-%D: Specifies the output file name format. %D is a placeholder for the current date and time.

• 192.168.0.0/24: Specifies the IP range to scan, in this case, all IP addresses from 192.168.0.0 to 192.168.0.255.

For a simpler verbose scan,

sudo nmap -v -A -sS -p- -O target

• sudo: Runs the command with administrative privileges.

• nmap: The command-line tool used for network exploration and security auditing.

• -v: Enables verbose output, providing more detailed information during the scan.

• -A: Enables aggressive scanning options, including OS detection, version detection, script scanning, and traceroute.

• -sS: Performs a TCP SYN scan, which is the default scan type for privileged users.

• -p-: Scans all 65,535 TCP ports.

• -O: Enables OS detection, which attempts to determine the operating system running on the target.

• target: Specifies the target IP address, DNS name, or CIDR range to scan.