use List::Util  qw( shuffle    );
use Devel::Size qw( total_size );

my ($x, %ip0, %ip1, %ip2, %ip3, %ip4, %ip5) = 31;

foreach my $i0 ((shuffle 1..254)[0..$x]) {
foreach my $i1 ((shuffle 1..254)[0..$x]) {
foreach my $i2 ((shuffle 1..254)[0..$x]) {
foreach my $i3 ((shuffle 1..254)[0..$x]) {
    $ip0{"$i0.$i1.$i2.$i3"}++;
    $ip1{"$i0.$i1"}{"$i2.$i3"}++;
    $ip2{$i0}{$i1}{$i2}{$i3}++;
    $ip3{pack "CCCC", $i0, $i1, $i2, $i3}++;
    $ip4{pack "CC", $i0, $i1}{pack "CC", $i2, $i3}++;
    $ip5{pack "C", $i0}{pack "C", $i1}{pack "C", $i2}{pack "C", $i3}++;
    }}}}

printf "{192.168.101.208}    : %9d\n", total_size (\%ip0);
printf "{192.168}{101.208}   : %9d\n", total_size (\%ip1);
printf "{192}{168}{101}{208} : %9d\n", total_size (\%ip2);
printf "{xC0xA8x65xD0}       : %9d\n", total_size (\%ip3);
printf "{xC0xA8}{x65xD0}     : %9d\n", total_size (\%ip4);
printf "{xC0}{xA8}{x65}{xD0} : %9d\n", total_size (\%ip5);


==>

{192.168.101.208}    : 116483356
{192.168}{101.208}   :  69879492
{192}{168}{101}{208} :  71176834
{xC0xA8x65xD0}       : 106954864
{xC0xA8}{x65xD0}     :  69611776
{xC0}{xA8}{x65}{xD0} :  71176690