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#!/usr/bin/perl
# Simple DHCP client - send a LeaseQuery (by IP) and receive the response
use IO::Socket::INET;
use Net::DHCP::Packet;
use Net::DHCP::Constants;
$usage = "usage: $0 DHCP_SERVER_IP DHCP_CLIENT_IP\n"; $ARGV[1] || die $usage;
# create a socket
$handle = IO::Socket::INET->new(Proto => 'udp',
Broadcast => 1,
PeerPort => '67',
LocalPort => '67',
PeerAddr => $ARGV[0])
or die "socket: $@"; # yes, it uses $@ here
# create DHCP Packet
$inform = Net::DHCP::Packet->new(
op => BOOTREQUEST(),
Htype => '0',
Hlen => '0',
Ciaddr => $ARGV[1],
Giaddr => $handle->sockhost(),
Xid => int(rand(0xFFFFFFFF)), # random xid
DHO_DHCP_MESSAGE_TYPE() => DHCPLEASEQUERY
);
# send request
$handle->send($inform->serialize()) or die "Error sending LeaseQuery: $!\n";
#receive response
$handle->recv($newmsg, 1024) or die;
$packet = Net::DHCP::Packet->new($newmsg);
print $packet->toString();
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