use IO::Select;
use IO::Socket::INET;
use Net::DHCP::Constants;
use Net::DHCP::Packet;

my $socket = IO::Socket::INET->new(Proto => 'udp',
                                   Broadcast => 1,
                                   PeerPort  => '67',
                                   LocalPort => '4111',
                                   PeerAddr  => '255.255.255.255')
  or die ($@);

# create and send DHCP Packet
my $disc = Net::DHCP::Packet->new(
              xid => int(rand(0xFFFFFFFF)),
              Flags => 0x8000, # ask for broadcast answer
              DHO_DHCP_MESSAGE_TYPE() => DHCPDISCOVER())
    or die "Can't create DHCP discover packet: $!";

$socket->send($disc->serialize())
    or die "Can't send DHCP discover packet: $!";

my @ready = IO::Select->new($socket)->can_read(5);
if (@ready) {
  my $newmsg;
  $socket->recv($newmsg, 1024)
      or die "Can't recv DHCP discover packet: $!";
  my $packet = Net::DHCP::Packet->new($newmsg);
  # site-local option 252 "auto-proxy-config"
  my $wpad = $packet->getOptionValue(252);