#!/usr/bin/perl -w
$|++;
use strict;
use IO::Socket;

my $response = IO::Socket::INET->new(Proto=>"udp",LocalPort=>2424)
  or die "Can't make UDP server: $@";

my $message = IO::Socket::INET->new(Proto=>"udp",PeerPort=>4242,PeerAddr=>"chmrr.mit.edu") 
  or die "Can't make UDP socket: $@";
$message->send("Ping!");

my ($datagram,$flags);
$response->recv($datagram,42,$flags);
print "Got message from ", $response->peerhost,", flags ",$flags || "none",": $datagram\n";

##</code><code>##

#!/usr/bin/perl -w
$|++;
use strict;
use IO::Socket;

my $server = IO::Socket::INET->new(LocalPort=>4242,Proto=>"udp")
  or die "Can't create UDP server: $@";
my ($datagram,$flags);

while ($server->recv($datagram,42,$flags)) {
  my $ipaddr = $server->peerhost;
  print "Oooh -- udp from $ipaddr, flags ",$flags || "none",": $datagram\n";
  my $response = IO::Socket::INET->new(Proto=>"udp",PeerHost=>$ipaddr,PeerPort=>2424);
  $response->send("PONG!");
}