use IO::Socket;

my $first_var = "64.219.21.1";
my $last_var  = "25";

my ($net,$first) = ($first_var   =~ /^(\d{1,3}\.\d{1,3}\.\d{1,3})\.(\d{1,3})$/ );
die "undetermined network part in $first_var.\n" unless $net;
die "undetermined host part in $first_var.\n" unless $first;

my ($last) = ($last_var =~ /^(\d{1,3})$/ );
die "undetermined host part in $last_var.\n" unless $last;

($last, $first) = ($first, $last) if $last < $first;

my @hosts = ($first..$last);

for ($li=0;$li<=$#hosts;$li++){ &scan() }