Another network scanner.
For example, you want to find possible free IP-addresses in the 10.0.10.1 – 10.0.10.1 range:
for i in {1..10}; do (ip="10.0.10.$i"; up=`ping -n -q -W3 -c1 $ip | fgrep transmitted | sed -e 's/.*100%.*/down/' -e 's/.*0%.*/up/'`;name=`host $ip | awk '!/NXDOMAIN/{print $NF}'`; echo $ip $up $name) 2>/dev/null & done | sort -n -t. -k4
Result:
10.0.10.1 down 10.0.10.2 down 10.0.10.3 up host1. 10.0.10.4 down 10.0.10.5 down myhost2.internal.domain. 10.0.10.6 up nas3. 10.0.10.7 down laptop. 10.0.10.8 down 10.0.10.9 up switch2. 10.0.10.10 down printer.