What’s going on with a known host?
Normal useful nmap command:
sudo nmap -A example.xed.ch
This needs root. The -A is OS with Version detection. Using -O instead works, but it isn’t as clever and can’t find the OS sometimes.
Looking for unknown hosts on a network range
This will take a long time but produce results about a /24 network:
sudo nmap -A 192.168.1.* sudo nmap -A 192.168.1.0/24
This one is from my updater script. Works pretty fast.
/usr/bin/nmap -sP 10.1.1.2-254 192.168.14.2-254 -oG - | /bin/grep "Status: Up" | /bin/sed "s/^.*(\\(.*\\)).*$/\\1/"