Question

What is the easiest way using common linux tools to check if a bunch of ip addresses belongs to given network? I just need a number of how many of given addresses belongs to given subnet. Lets say network is 192.16.55.40/27 and addresses is 192.16.55.45, 192.16.55.115, 88.87.45.8, 192.16.55.37, 192.16.55.60 and 192.16.55.210..

Answer 1

I’m not sure whether you consider Ruby as a ‘common linux tool’ but it has a nice module called IPAddr that has a method called include? for that.

require 'ipaddr'  net1 = IPAddr.new('192.168.2.0/24') net2 = IPAddr.new('192.168.2.100') net3 = IPAddr.new('192.168.3.0') p net1.include?(net2)     #=> true p net1.include?(net3)     #=> false