actually this script's working fine for localhost, and i got a reports from some ppl that this script is working fine too in their LAN, just to make sure i remade this script (well..actually it's only copied and pasted from ping.pm)..

##Update-2##
Well, i just found out that if we send single icmp packet to LOCALHOST we dont need a 'right value' for checksum, i mean we can put any numbers into $checksum, so for Localhost we dont need sub checksum
##EndOfUpdate-2##

use strict;
use Socket;

ping_icmp();

use constant ICMP_ECHOREPLY => 0; # ICMP packet types
use constant ICMP_ECHO => 8;
use constant ICMP_STRUCT => "C2 n3 A"; # Structure of a minimal ICMP p
+acket
use constant SUBCODE => 0; # No ICMP subcodefor ECHO and ECHOREPLY
use constant ICMP_FLAGS => 0; # No special flags for send or recv
use constant ICMP_PORT => 0; # No port with ICMP

sub ping_icmp
{
  my ($ip) = inet_aton('192.168.0.2');
  my ($saddr, $checksum, $msg, $len_msg);

  my $seq = 1;
  my $pid = $$ & 0xffff;
  $checksum = 0; # No checksum for starters
  my $data= "";
  $msg = pack(ICMP_STRUCT . 0,ICMP_ECHO,SUBCODE,$checksum,$pid,$seq,$d
+ata);
  $checksum =checksum($msg);
  $msg = pack(ICMP_STRUCT . 0,ICMP_ECHO,SUBCODE,$checksum,$pid,$seq,$d
+ata);
  $len_msg = length($msg);
  $saddr = sockaddr_in(ICMP_PORT, $ip);

  socket(SOCK,PF_INET,SOCK_RAW,getprotobyname('icmp'));
  send(SOCK,$msg,ICMP_FLAGS,$saddr);
}

sub checksum{
  my ($msg) = @_;
  my ($len_msg,$num_short,$short,$chk);

  $len_msg = length($msg);
  $num_short = int($len_msg / 2);
  $chk = 0;
  foreach $short (unpack("n$num_short", $msg)) {
    $chk += $short;
  }

  $chk += (unpack("C", substr($msg, $len_msg - 1, 1)) << 8) if $len_ms
+g % 2;
  $chk = ($chk >> 16) + ($chk & 0xffff); # Foldhigh into low
  return(~(($chk >> 16) + $chk) & 0xffff); # Again and complement
}
[download]

***UPDATE***
Because i still got weird result from this code (below), i'll strike this code

  my $buff;
  defined(recv(SOCK,$buff,256,0)) or die "error: $! \n";
  print "received: ", length($buff), " bytes\n";
 
  my($type,$subcode,$cksum,$recv_pid,$recv_seq)=unpack(ICMP_STRUCT,sub
+str($buff,20));
   if($type == ICMP_ECHOREPLY) {

    if($recv_pid != $pid) {

      print "icmp reply ignored (different pid) \n";
    }
    elsif($recv_seq != $seq) {
      print "icmp reply ignored (different seq) \n";
    }
    else {print "got icmp reply \n"};
    }
  else {
    print "not an icmp reply\n";
  }
}
[download]