Send a ping to each IP on a subnet

Question

Is there a command line based way to send pings to each computer in a subnet? Like

for(int i = 1; i < 254; i++)
    ping(192.168.1.i);

to enforce arp resolution?

Answer 1

I would suggest the use of fping with the mask option, since you are not restricting yourself in ping.

fping -g 192.168.1.0/24

The response will be easy to parse in a script:

192.168.1.1 is alive
192.168.1.2 is alive
192.168.1.3 is alive
192.168.1.5 is alive
...
192.168.1.4 is unreachable
192.168.1.6 is unreachable
192.168.1.7 is unreachable
...

Note: Using the argument -a will restrict the output to reachable ip addresses, you may want to use it otherwise fping will also print unreachable addresses:

fping -a -g 192.168.1.0/24

From man:

fping differs from ping in that you can specify any number of targets on the command line, or specify a file containing the lists of targets to ping. Instead of sending to one target until it times out or replies, fping will send out a ping packet and move on to the next target in a round-robin fashion.

More info: http://fping.org/