Server code -- in linux machine1

#!/usr/bin/perl -w
# server2way.pl - a server that reads from
# and writes to a client
use strict;
use IO::Socket;
use Sys::Hostname;
my $port=shift||9000;
my $sock = new IO::Socket::INET(
                   LocalHost => 'localhost',
                   LocalPort => $port,
                   Proto     => 'tcp',
                   Listen    => SOMAXCONN,
                   Reuse     => 2)
                   or die "no socket :$!";
STDOUT->autoflush(1);
my($new_sock, $buf);
while ($new_sock = $sock->accept()) {
    # got a client connection, so read
    # line by line until end-of-file
    while (defined($buf = <$new_sock>)) {
   # respond to client request using
   # a cleverly disguised switch
        # statement
        
   foreach ($buf) {
            /^PORT$/ and
            print($new_sock "$port\n"),
            print "$port\n",
            last;
            
            /^HELLO$/ and
                 print($new_sock "Hi\n"),
                 last;
                 
            /^NAME$/  and
                 print($new_sock hostname(),
                       "\n"),
                 last;
       /^DATE$/  and
                 print($new_sock
                       scalar(localtime),
                       "\n"),
                 last;
       # default case:
       print $new_sock "DEFAULT\n";
   }
    }
    close $new_sock;
}
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client1 --in linux machine1

#!/usr/bin/perl -w
# client2way.pl - a client that writes to
# and reads from a server
use strict;
use IO::Socket;
require "server2way.pl";
my $host = shift || 'localhost';
my $port = shift || 9000;
my $sock = new IO::Socket::INET(
                  PeerAddr => $host,
                  PeerPort => $port,
                  Proto    => 'tcp');
$sock or die "no socket :$!";
# send message to server
print $sock "PORT\n";
#print port number
print scalar <$sock>;
print $sock "HELLO\n";
# print server response to STDOUT
print scalar <$sock>;
# send and print more stuff
print $sock "NAME\n";
print scalar <$sock>;
print $sock "DATE\n";
print scalar <$sock>;
print $sock "NONE\n";
print scalar <$sock>;
close $sock;
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Client2 -- in windows machine

#!/usr/bin/perl -w
# client2way.pl - a client that writes to
# and reads from a server
use strict;
use IO::Socket;
#require "server2way.pl";
my $host = shift || '(I'm entering the address of the server machine h
+ere")';
my $port = shift || 9000;
my $sock = new IO::Socket::INET(
                  PeerAddr => $host,
                  PeerPort => $port,
                  Proto    => 'tcp');
$sock or die "no socket :$!";
# send message to server
print $sock "PORT\n";
#print port number
print scalar <$sock>;
print $sock "HELLO\n";
# print server response to STDOUT
print scalar <$sock>;
# send and print more stuff
print $sock "NAME\n";
print scalar <$sock>;
print $sock "DATE\n";
print scalar <$sock>;
print $sock "NONE\n";
print scalar <$sock>;
close $sock;
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How will server recognise the ping from server2, which is on different machine and which it is not even connected to.

thanks