A better sort:

sub pack_ip4 { pack 'C4', split /\./, @_ ? $_[0] : $_ }

for (
   map substr($_, 4),
   sort
   map pack_ip4($_).$_,
   keys %host_result
) {
   ...
}
[download]

That way, it'll sort the IPs numerically (.30 will be after .29 instead of after .3) without having to resort to adding zeroes.