use strict;
use warnings;

my $ip="158.21.17.45";
my @values = split(/\./, $ip); #<----Notice the Regex.

print $ip,"\t\t",$#values,"\n";

for my $val (@values){
        print "$val\n";
        }

exit(0);
[download]

158.21.17.45        3
158
21
17
45
[download]