Find out active IPs in a Linux LAN

Find out active IPs in a Linux LAN: "
If you are on a LAN and wish to find out which computers in it currently have access to that certain LAN, you can use the following command:

for ip in $(seq 1 254); do ping -c 1 192.168.1.$ip>/dev/null; [ $? -eq 0 ] && echo “192.168.1.$ip UP” || : ; done

This will ping each computer on the 192.168.1.x subnet one time, with a one second interval between pings. The output should be something like

192.168.1.1 UP
192.168.1.17 UP
192.168.1.24 UP
…

UPDATE:

Alternatively, you can use netdiscover:

sudo apt-get install netdiscover
netdiscover -r 192.168.1.0/24

This will scan all the computers in that particular address range and present the active ones in a table that also provides a MAC address and a MAC Vendor line. Thanks go out to angelblade for this information.

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