my $entry = 'permit ip host 10.11.1.1 192.168.100.0 0.0.0.255';
while ($entry =~ /(?:host){0}\s+(\d+\.\d+\.\d+\.\d+)\s+(\d+\.\d+\.\d+\.\d+)/g){
        # do something with $1 and $2
}


##</code><code>##

10.11.1.0  0.0.0.255 
192.168.100.0 0.0.0.255