61 #2

multi ips($num, 0) { $num < 255 ?? [ $num.Int.Str ] !! [,] }
multi ips($num, $l = 3) {
   gather for 1 .. 3 -> UInt $s {
      my $n = $num.substr: 0, $s;
      if $n <= 255 && $l <= $num.chars - $s <= $l * 3 {
         take "{ $n.Int }.$_" for ips $num.substr($s), $l - 1
      }
   }.unique
}


say ips "25525511135"