diff --git a/libraries/Ethernet/Client.cpp b/libraries/Ethernet/Client.cpp
index 96d5c7eedbd..7ae55d08d5f 100644
--- a/libraries/Ethernet/Client.cpp
+++ b/libraries/Ethernet/Client.cpp
@@ -16,7 +16,7 @@ uint16_t Client::_srcport = 1024;
 Client::Client(uint8_t sock) : _sock(sock) {
 }
 
-Client::Client(uint8_t *ip, uint16_t port) : _ip(ip), _port(port), _sock(MAX_SOCK_NUM) {
+Client::Client(IPAddress& ip, uint16_t port) : _ip(ip), _port(port), _sock(MAX_SOCK_NUM) {
 }
 
 uint8_t Client::connect() {
@@ -38,7 +38,7 @@ uint8_t Client::connect() {
   if (_srcport == 0) _srcport = 1024;
   socket(_sock, SnMR::TCP, _srcport, 0);
 
-  if (!::connect(_sock, _ip, _port)) {
+  if (!::connect(_sock, _ip.raw_address(), _port)) {
     _sock = MAX_SOCK_NUM;
     return 0;
   }
diff --git a/libraries/Ethernet/Client.h b/libraries/Ethernet/Client.h
index 8725f158a9c..e92e90e33f1 100644
--- a/libraries/Ethernet/Client.h
+++ b/libraries/Ethernet/Client.h
@@ -7,8 +7,8 @@ class Client : public Stream {
 
 public:
   Client();
-  Client(uint8_t);
-  Client(uint8_t *, uint16_t);
+  Client(uint8_t sock);
+  Client(IPAddress& ip, uint16_t port);
 
   uint8_t status();
   uint8_t connect();
@@ -31,7 +31,7 @@ class Client : public Stream {
 private:
   static uint16_t _srcport;
   uint8_t _sock;
-  uint8_t *_ip;
+  IPAddress _ip;
   uint16_t _port;
 };
 
diff --git a/libraries/Ethernet/Dhcp.cpp b/libraries/Ethernet/Dhcp.cpp
new file mode 100755
index 00000000000..8264b435bd1
--- /dev/null
+++ b/libraries/Ethernet/Dhcp.cpp
@@ -0,0 +1,341 @@
+// DHCP Library v0.3 - April 25, 2009
+// Author: Jordan Terrell - blog.jordanterrell.com
+
+#include "w5100.h"
+
+#include <string.h>
+#include <stdlib.h>
+#include "Dhcp.h"
+#include "wiring.h"
+#include "util.h"
+
+int DhcpClass::beginWithDHCP(uint8_t *mac, unsigned long timeout, unsigned long responseTimeout)
+{
+    uint8_t dhcp_state = STATE_DHCP_START;
+    uint8_t messageType = 0;
+  
+    // zero out _dhcpMacAddr, _dhcpSubnetMask, _dhcpGatewayIp, _dhcpLocalIp, _dhcpDhcpServerIp, _dhcpDnsServerIp
+    memset(_dhcpMacAddr, 0, 26); 
+
+    memcpy((void*)_dhcpMacAddr, (void*)mac, 6);
+  
+    // Pick an initial transaction ID
+    _dhcpTransactionId = random(1UL, 2000UL);
+    _dhcpInitialTransactionId = _dhcpTransactionId;
+
+    if (_dhcpUdpSocket.begin(DHCP_CLIENT_PORT) == 0)
+    {
+      // Couldn't get a socket
+      return 0;
+    }
+    
+    presend_DHCP();
+    
+    int result = 0;
+    
+    unsigned long startTime = millis();
+    
+    while(dhcp_state != STATE_DHCP_LEASED)
+    {
+        if(dhcp_state == STATE_DHCP_START)
+        {
+            _dhcpTransactionId++;
+            
+            send_DHCP_MESSAGE(DHCP_DISCOVER, ((millis() - startTime) / 1000));
+            dhcp_state = STATE_DHCP_DISCOVER;
+        }
+        else if(dhcp_state == STATE_DHCP_DISCOVER)
+        {
+            uint32_t respId;
+            messageType = parseDHCPResponse(responseTimeout, respId);
+            if(messageType == DHCP_OFFER)
+            {
+                // We'll use the transaction ID that the offer came with,
+                // rather than the one we were up to
+                _dhcpTransactionId = respId;
+                send_DHCP_MESSAGE(DHCP_REQUEST, ((millis() - startTime) / 1000));
+                dhcp_state = STATE_DHCP_REQUEST;
+            }
+        }
+        else if(dhcp_state == STATE_DHCP_REQUEST)
+        {
+            uint32_t respId;
+            messageType = parseDHCPResponse(responseTimeout, respId);
+            if(messageType == DHCP_ACK)
+            {
+                dhcp_state = STATE_DHCP_LEASED;
+                result = 1;
+            }
+            else if(messageType == DHCP_NAK)
+                dhcp_state = STATE_DHCP_START;
+        }
+        
+        if(messageType == 255)
+        {
+            messageType = 0;
+            dhcp_state = STATE_DHCP_START;
+        }
+        
+        if(result != 1 && ((millis() - startTime) > timeout))
+            break;
+    }
+    
+    // We're done with the socket now
+    _dhcpUdpSocket.stop();
+    _dhcpTransactionId++;
+    
+    return result;
+}
+
+void DhcpClass::presend_DHCP()
+{
+}
+
+void DhcpClass::send_DHCP_MESSAGE(uint8_t messageType, uint16_t secondsElapsed)
+{
+    uint8_t buffer[32];
+    memset(buffer, 0, 32);
+    IPAddress dest_addr( 255, 255, 255, 255 ); // Broadcast address
+
+    if (-1 == _dhcpUdpSocket.beginPacket(dest_addr, DHCP_SERVER_PORT))
+    {
+        // FIXME Need to return errors
+        return;
+    }
+
+    buffer[0] = DHCP_BOOTREQUEST;   // op
+    buffer[1] = DHCP_HTYPE10MB;     // htype
+    buffer[2] = DHCP_HLENETHERNET;  // hlen
+    buffer[3] = DHCP_HOPS;          // hops
+
+    // xid
+    unsigned long xid = htonl(_dhcpTransactionId);
+    memcpy(buffer + 4, &(xid), 4);
+
+    // 8, 9 - seconds elapsed
+    buffer[8] = ((secondsElapsed & 0xff00) >> 8);
+    buffer[9] = (secondsElapsed & 0x00ff);
+
+    // flags
+    unsigned short flags = htons(DHCP_FLAGSBROADCAST);
+    memcpy(buffer + 10, &(flags), 2);
+
+    // ciaddr: already zeroed
+    // yiaddr: already zeroed
+    // siaddr: already zeroed
+    // giaddr: already zeroed
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 28);
+
+    memset(buffer, 0, 32); // clear local buffer
+
+    memcpy(buffer, _dhcpMacAddr, 6); // chaddr
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 16);
+
+    memset(buffer, 0, 32); // clear local buffer
+
+    // leave zeroed out for sname && file
+    // put in W5100 transmit buffer x 6 (192 bytes)
+  
+    for(int i = 0; i < 6; i++) {
+        _dhcpUdpSocket.write(buffer, 32);
+    }
+  
+    // OPT - Magic Cookie
+    buffer[0] = (uint8_t)((MAGIC_COOKIE >> 24)& 0xFF);
+    buffer[1] = (uint8_t)((MAGIC_COOKIE >> 16)& 0xFF);
+    buffer[2] = (uint8_t)((MAGIC_COOKIE >> 8)& 0xFF);
+    buffer[3] = (uint8_t)(MAGIC_COOKIE& 0xFF);
+
+    // OPT - message type
+    buffer[4] = dhcpMessageType;
+    buffer[5] = 0x01;
+    buffer[6] = messageType; //DHCP_REQUEST;
+
+    // OPT - client identifier
+    buffer[7] = dhcpClientIdentifier;
+    buffer[8] = 0x07;
+    buffer[9] = 0x01;
+    memcpy(buffer + 10, _dhcpMacAddr, 6);
+
+    // OPT - host name
+    buffer[16] = hostName;
+    buffer[17] = strlen(HOST_NAME) + 3; // length of hostname + last 3 bytes of mac address
+    strcpy((char*)&(buffer[18]), HOST_NAME);
+
+    buffer[24] = _dhcpMacAddr[3];
+    buffer[25] = _dhcpMacAddr[4];
+    buffer[26] = _dhcpMacAddr[5];
+
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 27);
+
+    if(messageType == DHCP_REQUEST)
+    {
+        buffer[0] = dhcpRequestedIPaddr;
+        buffer[1] = 0x04;
+        buffer[2] = _dhcpLocalIp[0];
+        buffer[3] = _dhcpLocalIp[1];
+        buffer[4] = _dhcpLocalIp[2];
+        buffer[5] = _dhcpLocalIp[3];
+
+        buffer[6] = dhcpServerIdentifier;
+        buffer[7] = 0x04;
+        buffer[8] = _dhcpDhcpServerIp[0];
+        buffer[9] = _dhcpDhcpServerIp[1];
+        buffer[10] = _dhcpDhcpServerIp[2];
+        buffer[11] = _dhcpDhcpServerIp[3];
+
+        //put data in W5100 transmit buffer
+        _dhcpUdpSocket.write(buffer, 12);
+    }
+    
+    buffer[0] = dhcpParamRequest;
+    buffer[1] = 0x06;
+    buffer[2] = subnetMask;
+    buffer[3] = routersOnSubnet;
+    buffer[4] = dns;
+    buffer[5] = domainName;
+    buffer[6] = dhcpT1value;
+    buffer[7] = dhcpT2value;
+    buffer[8] = endOption;
+    
+    //put data in W5100 transmit buffer
+    _dhcpUdpSocket.write(buffer, 9);
+
+    _dhcpUdpSocket.endPacket();
+}
+
+uint8_t DhcpClass::parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId)
+{
+    uint8_t type = 0;
+    uint8_t opt_len = 0;
+     
+    unsigned long startTime = millis();
+
+    while(_dhcpUdpSocket.parsePacket() <= 0)
+    {
+        if((millis() - startTime) > responseTimeout)
+        {
+            return 255;
+        }
+        delay(50);
+    }
+    // start reading in the packet
+    RIP_MSG_FIXED fixedMsg;
+    _dhcpUdpSocket.read((uint8_t*)&fixedMsg, sizeof(RIP_MSG_FIXED));
+  
+    if(fixedMsg.op == DHCP_BOOTREPLY && _dhcpUdpSocket.remotePort() == DHCP_SERVER_PORT)
+    {
+        transactionId = ntohl(fixedMsg.xid);
+        if(memcmp(fixedMsg.chaddr, _dhcpMacAddr, 6) != 0 || (transactionId < _dhcpInitialTransactionId) || (transactionId > _dhcpTransactionId))
+        {
+            // Need to read the rest of the packet here regardless
+            _dhcpUdpSocket.flush();
+            return 0;
+        }
+
+        memcpy(_dhcpLocalIp, fixedMsg.yiaddr, 4);
+
+        // Skip to the option part
+        // Doing this a byte at a time so we don't have to put a big buffer
+        // on the stack (as we don't have lots of memory lying around)
+        for (int i =0; i < (240 - sizeof(RIP_MSG_FIXED)); i++)
+        {
+            _dhcpUdpSocket.read(); // we don't care about the returned byte
+        }
+
+        while (_dhcpUdpSocket.available() > 0) 
+        {
+            switch (_dhcpUdpSocket.read()) 
+            {
+                case endOption :
+                    break;
+                    
+                case padOption :
+                    break;
+                
+                case dhcpMessageType :
+                    opt_len = _dhcpUdpSocket.read();
+                    type = _dhcpUdpSocket.read();
+                    break;
+                
+                case subnetMask :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpSubnetMask, 4);
+                    break;
+                
+                case routersOnSubnet :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpGatewayIp, 4);
+                    break;
+                
+                case dns :
+                    opt_len = _dhcpUdpSocket.read();
+                    _dhcpUdpSocket.read(_dhcpDnsServerIp, 4);
+                    break;
+                
+                case dhcpServerIdentifier :
+                    opt_len = _dhcpUdpSocket.read();
+                    if( *((uint32_t*)_dhcpDhcpServerIp) == 0 || 
+                        IPAddress(_dhcpDhcpServerIp) == _dhcpUdpSocket.remoteIP() )
+                    {
+                        _dhcpUdpSocket.read(_dhcpDhcpServerIp, sizeof(_dhcpDhcpServerIp));
+                    }
+                    else
+                    {
+                        // Skip over the rest of this option
+                        while (opt_len--)
+                        {
+                            _dhcpUdpSocket.read();
+                        }
+                    }
+                    break;
+                
+                case dhcpIPaddrLeaseTime :
+                default :
+                    opt_len = _dhcpUdpSocket.read();
+                    // Skip over the rest of this option
+                    while (opt_len--)
+                    {
+                        _dhcpUdpSocket.read();
+                    }
+                    break;
+            }
+        }
+    }
+
+    // Need to skip to end of the packet regardless here
+    _dhcpUdpSocket.flush();
+
+    return type;
+}
+
+IPAddress DhcpClass::getLocalIp()
+{
+    return IPAddress(_dhcpLocalIp);
+}
+
+IPAddress DhcpClass::getSubnetMask()
+{
+    return IPAddress(_dhcpSubnetMask);
+}
+
+IPAddress DhcpClass::getGatewayIp()
+{
+    return IPAddress(_dhcpGatewayIp);
+}
+
+IPAddress DhcpClass::getDhcpServerIp()
+{
+    return IPAddress(_dhcpDhcpServerIp);
+}
+
+IPAddress DhcpClass::getDnsServerIp()
+{
+    return IPAddress(_dhcpDnsServerIp);
+}
+
diff --git a/libraries/Ethernet/Dhcp.h b/libraries/Ethernet/Dhcp.h
new file mode 100755
index 00000000000..c0034940c27
--- /dev/null
+++ b/libraries/Ethernet/Dhcp.h
@@ -0,0 +1,158 @@
+// DHCP Library v0.3 - April 25, 2009
+// Author: Jordan Terrell - blog.jordanterrell.com
+
+#ifndef Dhcp_h
+#define Dhcp_h
+
+#include "Udp.h"
+
+/* DHCP state machine. */
+#define STATE_DHCP_START 0
+#define	STATE_DHCP_DISCOVER	1
+#define	STATE_DHCP_REQUEST	2
+#define	STATE_DHCP_LEASED	3
+#define	STATE_DHCP_REREQUEST	4
+#define	STATE_DHCP_RELEASE	5
+
+#define DHCP_FLAGSBROADCAST	0x8000
+
+/* UDP port numbers for DHCP */
+#define	DHCP_SERVER_PORT	67	/* from server to client */
+#define DHCP_CLIENT_PORT	68	/* from client to server */
+
+/* DHCP message OP code */
+#define DHCP_BOOTREQUEST	1
+#define DHCP_BOOTREPLY		2
+
+/* DHCP message type */
+#define	DHCP_DISCOVER		1
+#define DHCP_OFFER		  2
+#define	DHCP_REQUEST		3
+#define	DHCP_DECLINE		4
+#define	DHCP_ACK		    5
+#define DHCP_NAK		    6
+#define	DHCP_RELEASE		7
+#define DHCP_INFORM		  8
+
+#define DHCP_HTYPE10MB		1
+#define DHCP_HTYPE100MB		2
+
+#define DHCP_HLENETHERNET	6
+#define DHCP_HOPS		0
+#define DHCP_SECS		0
+
+#define MAGIC_COOKIE		0x63825363
+#define MAX_DHCP_OPT	16
+
+#define HOST_NAME "WIZnet"
+
+enum
+{
+	padOption		=	0,
+	subnetMask		=	1,
+	timerOffset		=	2,
+	routersOnSubnet		=	3,
+	/* timeServer		=	4,
+	nameServer		=	5,*/
+	dns			=	6,
+	/*logServer		=	7,
+	cookieServer		=	8,
+	lprServer		=	9,
+	impressServer		=	10,
+	resourceLocationServer	=	11,*/
+	hostName		=	12,
+	/*bootFileSize		=	13,
+	meritDumpFile		=	14,*/
+	domainName		=	15,
+	/*swapServer		=	16,
+	rootPath		=	17,
+	extentionsPath		=	18,
+	IPforwarding		=	19,
+	nonLocalSourceRouting	=	20,
+	policyFilter		=	21,
+	maxDgramReasmSize	=	22,
+	defaultIPTTL		=	23,
+	pathMTUagingTimeout	=	24,
+	pathMTUplateauTable	=	25,
+	ifMTU			=	26,
+	allSubnetsLocal		=	27,
+	broadcastAddr		=	28,
+	performMaskDiscovery	=	29,
+	maskSupplier		=	30,
+	performRouterDiscovery	=	31,
+	routerSolicitationAddr	=	32,
+	staticRoute		=	33,
+	trailerEncapsulation	=	34,
+	arpCacheTimeout		=	35,
+	ethernetEncapsulation	=	36,
+	tcpDefaultTTL		=	37,
+	tcpKeepaliveInterval	=	38,
+	tcpKeepaliveGarbage	=	39,
+	nisDomainName		=	40,
+	nisServers		=	41,
+	ntpServers		=	42,
+	vendorSpecificInfo	=	43,
+	netBIOSnameServer	=	44,
+	netBIOSdgramDistServer	=	45,
+	netBIOSnodeType		=	46,
+	netBIOSscope		=	47,
+	xFontServer		=	48,
+	xDisplayManager		=	49,*/
+	dhcpRequestedIPaddr	=	50,
+	dhcpIPaddrLeaseTime	=	51,
+	/*dhcpOptionOverload	=	52,*/
+	dhcpMessageType		=	53,
+	dhcpServerIdentifier	=	54,
+	dhcpParamRequest	=	55,
+	/*dhcpMsg			=	56,
+	dhcpMaxMsgSize		=	57,*/
+	dhcpT1value		=	58,
+	dhcpT2value		=	59,
+	/*dhcpClassIdentifier	=	60,*/
+	dhcpClientIdentifier	=	61,
+	endOption		=	255
+};
+
+typedef struct _RIP_MSG_FIXED
+{
+	uint8_t  op; 
+	uint8_t  htype; 
+	uint8_t  hlen;
+	uint8_t  hops;
+	uint32_t xid;
+	uint16_t secs;
+	uint16_t flags;
+	uint8_t  ciaddr[4];
+	uint8_t  yiaddr[4];
+	uint8_t  siaddr[4];
+	uint8_t  giaddr[4];
+	uint8_t  chaddr[6];
+}RIP_MSG_FIXED;
+
+class DhcpClass {
+private:
+  uint32_t _dhcpInitialTransactionId;
+  uint32_t _dhcpTransactionId;
+  uint8_t  _dhcpMacAddr[6];
+  uint8_t  _dhcpLocalIp[4];
+  uint8_t  _dhcpSubnetMask[4];
+  uint8_t  _dhcpGatewayIp[4];
+  uint8_t  _dhcpDhcpServerIp[4];
+  uint8_t  _dhcpDnsServerIp[4];
+  UDP _dhcpUdpSocket;
+  
+  void presend_DHCP();
+  void send_DHCP_MESSAGE(uint8_t, uint16_t);
+  
+  uint8_t parseDHCPResponse(unsigned long responseTimeout, uint32_t& transactionId);
+public:
+  IPAddress getLocalIp();
+  IPAddress getSubnetMask();
+  IPAddress getGatewayIp();
+  IPAddress getDhcpServerIp();
+  IPAddress getDnsServerIp();
+  
+  int beginWithDHCP(uint8_t *, unsigned long timeout = 60000, unsigned long responseTimeout = 4000);
+};
+
+#endif
diff --git a/libraries/Ethernet/Ethernet.cpp b/libraries/Ethernet/Ethernet.cpp
index 91cbacd3966..937f5b4f9a1 100644
--- a/libraries/Ethernet/Ethernet.cpp
+++ b/libraries/Ethernet/Ethernet.cpp
@@ -1,5 +1,6 @@
 #include "w5100.h"
 #include "Ethernet.h"
+#include "Dhcp.h"
 
 // XXX: don't make assumptions about the value of MAX_SOCK_NUM.
 uint8_t EthernetClass::_state[MAX_SOCK_NUM] = { 
@@ -7,30 +8,78 @@ uint8_t EthernetClass::_state[MAX_SOCK_NUM] = {
 uint16_t EthernetClass::_server_port[MAX_SOCK_NUM] = { 
   0, 0, 0, 0 };
 
-void EthernetClass::begin(uint8_t *mac, uint8_t *ip)
+int EthernetClass::begin(uint8_t *mac_address)
 {
-  uint8_t gateway[4];
-  gateway[0] = ip[0];
-  gateway[1] = ip[1];
-  gateway[2] = ip[2];
+  DhcpClass dhcp;
+
+  // Initialise the basic info
+  W5100.init();
+  W5100.setMACAddress(mac_address);
+  W5100.setIPAddress(IPAddress(0,0,0,0).raw_address());
+
+  // Now try to get our config info from a DHCP server
+  int ret = dhcp.beginWithDHCP(mac_address);
+  if(ret == 1)
+  {
+    // We've successfully found a DHCP server and got our configuration info, so set things
+    // accordingly
+    W5100.setIPAddress(dhcp.getLocalIp().raw_address());
+    W5100.setGatewayIp(dhcp.getGatewayIp().raw_address());
+    W5100.setSubnetMask(dhcp.getSubnetMask().raw_address());
+    _dnsServerAddress = dhcp.getDnsServerIp();
+  }
+
+  return ret;
+}
+
+void EthernetClass::begin(uint8_t *mac_address, IPAddress local_ip)
+{
+  // Assume the gateway will be the machine on the same network as the local IP
+  // but with last octet being '1'
+  IPAddress gateway = local_ip;
   gateway[3] = 1;
-  begin(mac, ip, gateway);
+  begin(mac_address, local_ip, gateway);
 }
 
-void EthernetClass::begin(uint8_t *mac, uint8_t *ip, uint8_t *gateway)
+void EthernetClass::begin(uint8_t *mac_address, IPAddress local_ip, IPAddress gateway)
 {
-  uint8_t subnet[] = { 
-    255, 255, 255, 0   };
-  begin(mac, ip, gateway, subnet);
+  IPAddress subnet(255, 255, 255, 0);
+  begin(mac_address, local_ip, gateway, subnet);
 }
 
-void EthernetClass::begin(uint8_t *mac, uint8_t *ip, uint8_t *gateway, uint8_t *subnet)
+void EthernetClass::begin(uint8_t *mac, IPAddress local_ip, IPAddress gateway, IPAddress subnet)
 {
   W5100.init();
   W5100.setMACAddress(mac);
-  W5100.setIPAddress(ip);
-  W5100.setGatewayIp(gateway);
-  W5100.setSubnetMask(subnet);
+  W5100.setIPAddress(local_ip._address);
+  W5100.setGatewayIp(gateway._address);
+  W5100.setSubnetMask(subnet._address);
+}
+
+IPAddress EthernetClass::localIP()
+{
+  IPAddress ret;
+  W5100.getIPAddress(ret.raw_address());
+  return ret;
+}
+
+IPAddress EthernetClass::subnetMask()
+{
+  IPAddress ret;
+  W5100.getSubnetMask(ret.raw_address());
+  return ret;
+}
+
+IPAddress EthernetClass::gatewayIP()
+{
+  IPAddress ret;
+  W5100.getGatewayIp(ret.raw_address());
+  return ret;
+}
+
+IPAddress EthernetClass::dnsServerIP()
+{
+  return _dnsServerAddress;
 }
 
 EthernetClass Ethernet;
diff --git a/libraries/Ethernet/Ethernet.h b/libraries/Ethernet/Ethernet.h
index a91f1aa177b..fdf0b7f39b7 100644
--- a/libraries/Ethernet/Ethernet.h
+++ b/libraries/Ethernet/Ethernet.h
@@ -3,6 +3,7 @@
 
 #include <inttypes.h>
 //#include "w5100.h"
+#include "IPAddress.h"
 #include "Client.h"
 #include "Server.h"
 
@@ -10,12 +11,23 @@
 
 class EthernetClass {
 private:
+  IPAddress _dnsServerAddress;
 public:
   static uint8_t _state[MAX_SOCK_NUM];
   static uint16_t _server_port[MAX_SOCK_NUM];
-  void begin(uint8_t *, uint8_t *);
-  void begin(uint8_t *, uint8_t *, uint8_t *);
-  void begin(uint8_t *, uint8_t *, uint8_t *, uint8_t *);
+  // Initialise the Ethernet shield to use the provided MAC address and gain the rest of the
+  // configuration through DHCP.
+  // Returns 0 if the DHCP configuration failed, and 1 if it succeeded
+  int begin(uint8_t *mac_address);
+  void begin(uint8_t *mac_address, IPAddress local_ip);
+  void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress gateway);
+  void begin(uint8_t *mac_address, IPAddress local_ip, IPAddress gateway, IPAddress subnet);
+
+  IPAddress localIP();
+  IPAddress subnetMask();
+  IPAddress gatewayIP();
+  IPAddress dnsServerIP();
+
   friend class Client;
   friend class Server;
 };
diff --git a/libraries/Ethernet/IPAddress.cpp b/libraries/Ethernet/IPAddress.cpp
new file mode 100644
index 00000000000..408d518a0e7
--- /dev/null
+++ b/libraries/Ethernet/IPAddress.cpp
@@ -0,0 +1,44 @@
+
+#include <WProgram.h>
+#include <IPAddress.h>
+
+IPAddress::IPAddress()
+{
+    memset(_address, 0, sizeof(_address));
+}
+
+IPAddress::IPAddress(uint8_t first_octet, uint8_t second_octet, uint8_t third_octet, uint8_t fourth_octet)
+{
+    _address[0] = first_octet;
+    _address[1] = second_octet;
+    _address[2] = third_octet;
+    _address[3] = fourth_octet;
+}
+
+IPAddress::IPAddress(uint32_t address)
+{
+    memcpy(_address, &address, sizeof(_address));
+}
+
+IPAddress::IPAddress(const uint8_t *address)
+{
+    memcpy(_address, address, sizeof(_address));
+}
+
+IPAddress& IPAddress::operator=(const uint8_t *address)
+{
+    memcpy(_address, address, sizeof(_address));
+    return *this;
+}
+
+IPAddress& IPAddress::operator=(uint32_t address)
+{
+    memcpy(_address, (const uint8_t *)&address, sizeof(_address));
+    return *this;
+}
+
+bool IPAddress::operator==(const uint8_t* addr)
+{
+    return memcmp(addr, _address, sizeof(_address)) == 0;
+}
+
diff --git a/libraries/Ethernet/IPAddress.h b/libraries/Ethernet/IPAddress.h
new file mode 100644
index 00000000000..1d19bbd222b
--- /dev/null
+++ b/libraries/Ethernet/IPAddress.h
@@ -0,0 +1,68 @@
+/*
+ *
+ * MIT License:
+ * Copyright (c) 2011 Adrian McEwen
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ *
+ * adrianm@mcqn.com 1/1/2011
+ */
+
+#ifndef IPAddress_h
+#define IPAddress_h
+
+// A class to make it easier to handle and pass around IP addresses
+
+class IPAddress {
+private:
+    uint8_t _address[4];  // IPv4 address
+    // Access the raw byte array containing the address.  Because this returns a pointer
+    // to the internal structure rather than a copy of the address this function should only
+    // be used when you know that the usage of the returned uint8_t* will be transient and not
+    // stored.
+    uint8_t* raw_address() { return _address; };
+
+public:
+    // Constructors
+    IPAddress();
+    IPAddress(uint8_t first_octet, uint8_t second_octet, uint8_t third_octet, uint8_t fourth_octet);
+    IPAddress(uint32_t address);
+    IPAddress(const uint8_t *address);
+
+    // Overloaded cast operator to allow IPAddress objects to be used where a pointer
+    // to a four-byte uint8_t array is expected
+    operator uint32_t() { return *((uint32_t*)_address); };
+    bool operator==(const IPAddress& addr) { return (*((uint32_t*)_address)) == (*((uint32_t*)addr._address)); };
+    bool operator==(const uint8_t* addr);
+
+    // Overloaded index operator to allow getting and setting individual octets of the address
+    uint8_t operator[](int index) const { return _address[index]; };
+    uint8_t& operator[](int index) { return _address[index]; };
+
+    // Overloaded copy operators to allow initialisation of IPAddress objects from other types
+    IPAddress& operator=(const uint8_t *address);
+    IPAddress& operator=(uint32_t address);
+
+    friend class EthernetClass;
+    friend class UDP;
+    friend class Client;
+    friend class Server;
+    friend class DhcpClass;
+};
+
+#endif
diff --git a/libraries/Ethernet/Udp.cpp b/libraries/Ethernet/Udp.cpp
index 07c454df228..a8c98c3f49b 100644
--- a/libraries/Ethernet/Udp.cpp
+++ b/libraries/Ethernet/Udp.cpp
@@ -56,106 +56,111 @@ uint8_t UDP::begin(uint16_t port) {
   return 1;
 }
 
-/* Send packet contained in buf of length len to peer at specified ip, and port */
-/* Use this function to transmit binary data that might contain 0x00 bytes*/
-/* This function returns sent data size for success else -1. */
-uint16_t UDP::sendPacket(uint8_t * buf, uint16_t len,  uint8_t * ip, uint16_t port){
-  return sendto(_sock,(const uint8_t *)buf,len,ip,port);
-}
-
-/* Send  zero-terminated string str as packet to peer at specified ip, and port */
-/* This function returns sent data size for success else -1. */
-uint16_t UDP::sendPacket(const char str[], uint8_t * ip, uint16_t port){	
-  // compute strlen
-  const char *s;
-  for(s = str; *s; ++s);
-  uint16_t len = (s-str);
-  // send packet
-  return sendto(_sock,(const uint8_t *)str,len,ip,port);
-}
 /* Is data available in rx buffer? Returns 0 if no, number of available bytes if yes. 
  * returned value includes 8 byte UDP header!*/
 int UDP::available() {
   return W5100.getRXReceivedSize(_sock);
 }
 
+/* Release any resources being used by this UDP instance */
+void UDP::stop()
+{
+  if (_sock == MAX_SOCK_NUM)
+    return;
 
-/* Read a received packet into buffer buf (which is of maximum length len); */
-/* store calling ip and port as well. Call available() to make sure data is ready first. */
-/* NOTE: I don't believe len is ever checked in implementation of recvfrom(),*/
-/*       so it's easy to overflow buffer. so we check and truncate. */
-/* returns number of bytes read, or negative number of bytes we would have needed if we truncated */
-int UDP::readPacket(uint8_t * buf, uint16_t bufLen, uint8_t *ip, uint16_t *port) {
-  int packetLen = available()-8; //skip UDP header;
-  if(packetLen < 0 ) return 0; // no real data here	
-  if(packetLen > (int)bufLen) {
-    //packet is too large - truncate
-    //HACK - hand-parse the UDP packet using TCP recv method
-    uint8_t tmpBuf[8];
-    int i;
-    //read 8 header bytes and get IP and port from it
-    recv(_sock,tmpBuf,8);
-    ip[0] = tmpBuf[0];
-    ip[1] = tmpBuf[1];
-    ip[2] = tmpBuf[2];
-    ip[3] = tmpBuf[3];
-    *port = tmpBuf[4];
-    *port = (*port << 8) + tmpBuf[5];
-
-    //now copy first (bufLen) bytes into buf		
-    for(i=0;i<(int)bufLen;i++) {
-      recv(_sock,tmpBuf,1);
-      buf[i]=tmpBuf[0];
-    }
+  close(_sock);
 
-    //and just read the rest byte by byte and throw it away
-    while(available()) {
-      recv(_sock,tmpBuf,1);
-    }
+  EthernetClass::_server_port[_sock] = 0;
+  _sock = MAX_SOCK_NUM;
+}
 
-    return (-1*packetLen);
+int UDP::beginPacket(IPAddress ip, uint16_t port)
+{
+  _offset = 0;
+  return startUDP(_sock, ip.raw_address(), port);
+}
 
-    //ALTERNATIVE: requires stdlib - takes a bunch of space
-    /*//create new buffer and read everything into it
-     		uint8_t * tmpBuf = (uint8_t *)malloc(packetLen);
-     		recvfrom(_sock,tmpBuf,packetLen,ip,port);
-     		if(!tmpBuf) return 0; //couldn't allocate
-     		// copy first bufLen bytes
-     		for(unsigned int i=0; i<bufLen; i++) {
-     			buf[i]=tmpBuf[i];
-     		}
-     		//free temp buffer
-     		free(tmpBuf);
-     		*/
+int UDP::endPacket()
+{
+  return sendUDP(_sock);
+}
 
+void UDP::write(uint8_t byte)
+{
+  write(&byte, 1);
+}
 
-  } 
-  return recvfrom(_sock,buf,bufLen,ip,port);
+void UDP::write(const char *str)
+{
+  size_t len = strlen(str);
+  write((const uint8_t *)str, len);
 }
 
-/* Read a received packet, throw away peer's ip and port.  See note above. */
-int UDP::readPacket(uint8_t * buf, uint16_t len) {
-  uint8_t ip[4];
-  uint16_t port[1];
-  return recvfrom(_sock,buf,len,ip,port);
+void UDP::write(const uint8_t *buffer, size_t size)
+{
+  uint16_t bytes_written = bufferData(_sock, _offset, buffer, size);
+  _offset += bytes_written;
 }
 
-int UDP::readPacket(char * buf, uint16_t bufLen, uint8_t *ip, uint16_t &port) {
-uint16_t myPort;
-uint16_t ret = readPacket( (byte*)buf, bufLen, ip, &myPort);
-port = myPort;
-return ret;
+int UDP::parsePacket()
+{
+  //HACK - hand-parse the UDP packet using TCP recv method
+  uint8_t tmpBuf[8];
+  int ret =0;	
+  //read 8 header bytes and get IP and port from it
+  ret = recv(_sock,tmpBuf,8);
+  if (ret > 0)
+  {
+    _remoteIP = tmpBuf;
+    _remotePort = tmpBuf[4];
+    _remotePort = (_remotePort << 8) + tmpBuf[5];
+    // When we get here, any remaining bytes are the data
+    ret = available();
+  }
+  return ret;
 }
 
-/* Release any resources being used by this UDP instance */
-void UDP::stop()
+int UDP::read()
 {
-  if (_sock == MAX_SOCK_NUM)
-    return;
+  uint8_t byte;
+  if (recv(_sock, &byte, 1) > 0)
+  {
+    // We read things without any problems
+    return byte;
+  }
+  // If we get here, there's no data available
+  return -1;
+}
 
-  close(_sock);
+int UDP::read(unsigned char* buffer, size_t len)
+{
+  /* In the readPacket that copes with truncating packets, the buffer was
+     filled with this code.  Not sure why it loops round reading out a byte
+     at a time.
+  int i;
+  for(i=0;i<(int)bufLen;i++) {
+    recv(_sock,tmpBuf,1);
+    buf[i]=tmpBuf[0];
+  }
+  */
+  return recv(_sock, buffer, len);
+}
 
-  EthernetClass::_server_port[_sock] = 0;
-  _sock = MAX_SOCK_NUM;
+int UDP::peek()
+{
+  uint8_t b;
+  // Unlike recv, peek doesn't check to see if there's any data available, so we must
+  if (!available())
+    return -1;
+  ::peek(_sock, &b);
+  return b;
+}
+
+void UDP::flush()
+{
+  while (available())
+  {
+    read();
+  }
 }
 
diff --git a/libraries/Ethernet/Udp.h b/libraries/Ethernet/Udp.h
index c801ee277cd..8cd3b065a1b 100644
--- a/libraries/Ethernet/Udp.h
+++ b/libraries/Ethernet/Udp.h
@@ -37,28 +37,60 @@
 #ifndef udp_h
 #define udp_h
 
+#include <Stream.h>
+#include <IPAddress.h>
+
 #define UDP_TX_PACKET_MAX_SIZE 24
 
-class UDP {
+class UDP : public Stream {
 private:
   uint8_t _sock;  // socket ID for Wiz5100
   uint16_t _port; // local port to listen on
+  IPAddress _remoteIP; // remote IP address for the incoming packet whilst it's being processed
+  uint16_t _remotePort; // remote port for the incoming packet whilst it's being processed
+  uint16_t _offset; // offset into the packet being sent
 
 public:
-  UDP();
+  UDP();  // Constructor
   uint8_t begin(uint16_t);	// initialize, start listening on specified port. Returns 1 if successful, 0 if there are no sockets available to use
-  int available();								// has data been received?
+  void stop();  // Finish with the UDP socket
+
+  // Sending UDP packets
+  
+  // Start building up a packet to send to the remote host specific in ip and port
+  // Returns 1 if successful, 0 if there was a problem with the supplied IP address or port
+  int beginPacket(IPAddress ip, uint16_t port);
+  // Finish off this packet and send it
+  // Returns 1 if the packet was sent successfully, 0 if there was an error
+  int endPacket();
+  // Write a single byte into the packet
+  virtual void write(uint8_t);
+  // Write a string of characters into the packet
+  virtual void write(const char *str);
+  // Write size bytes from buffer into the packet
+  virtual void write(const uint8_t *buffer, size_t size);
 
-  // C-style buffer-oriented functions
-  uint16_t sendPacket(uint8_t *, uint16_t, uint8_t *, uint16_t); //send a packet to specified peer 
-  uint16_t sendPacket(const char[], uint8_t *, uint16_t);  //send a string as a packet to specified peer
-  int readPacket(uint8_t *, uint16_t);		// read a received packet 
-  int readPacket(uint8_t *, uint16_t, uint8_t *, uint16_t *);		// read a received packet, also return sender's ip and port 	
-  // readPacket that fills a character string buffer
-  int readPacket(char *, uint16_t, uint8_t *, uint16_t &);
+  // Start processing the next available incoming packet
+  // Returns the size of the packet in bytes, or 0 if no packets are available
+  int parsePacket();
+  // Number of bytes remaining in the current packet
+  virtual int available();
+  // Read a single byte from the current packet
+  virtual int read();
+  // Read up to len bytes from the current packet and place them into buffer
+  // Returns the number of bytes read, or 0 if none are available
+  virtual int read(unsigned char* buffer, size_t len);
+  // Read up to len characters from the current packet and place them into buffer
+  // Returns the number of characters read, or 0 if none are available
+  virtual int read(char* buffer, size_t len) { return read((unsigned char*)buffer, len); };
+  // Return the next byte from the current packet without moving on to the next byte
+  virtual int peek();
+  virtual void flush();	// Finish reading the current packet
 
-  // Finish with the UDP socket
-  void stop();
+  // Return the IP address of the host who sent the current incoming packet
+  IPAddress remoteIP() { return _remoteIP; };
+  // Return the port of the host who sent the current incoming packet
+  uint16_t remotePort() { return _remotePort; };
 };
 
 #endif
diff --git a/libraries/Ethernet/examples/BarometricPressureWebServer/BarometricPressureWebServer.pde b/libraries/Ethernet/examples/BarometricPressureWebServer/BarometricPressureWebServer.pde
index a58433fed5b..3f43d96dbc0 100644
--- a/libraries/Ethernet/examples/BarometricPressureWebServer/BarometricPressureWebServer.pde
+++ b/libraries/Ethernet/examples/BarometricPressureWebServer/BarometricPressureWebServer.pde
@@ -31,12 +31,9 @@
 byte mac[] = { 
   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
 // assign an IP address for the controller:
-byte ip[] = { 
-  192,168,1,20 };
-byte gateway[] = {
-  192,168,1,1};	
-byte subnet[] = { 
-  255, 255, 255, 0 };
+IPAddress ip(192,168,1,20);
+IPAddress gateway(192,168,1,1);	
+IPAddress subnet(255, 255, 255, 0);
 
 
 // Initialize the Ethernet server library
diff --git a/libraries/Ethernet/examples/ChatServer/ChatServer.pde b/libraries/Ethernet/examples/ChatServer/ChatServer.pde
index 50ae01408b8..8267a5dd45c 100644
--- a/libraries/Ethernet/examples/ChatServer/ChatServer.pde
+++ b/libraries/Ethernet/examples/ChatServer/ChatServer.pde
@@ -24,9 +24,9 @@
 // The IP address will be dependent on your local network.
 // gateway and subnet are optional:
 byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
-byte ip[] = { 192,168,1, 177 };
-byte gateway[] = { 192,168,1, 1 };
-byte subnet[] = { 255, 255, 0, 0 };
+IPAddress ip(192,168,1, 177);
+IPAddress gateway(192,168,1, 1);
+IPAddress subnet(255, 255, 0, 0);
 
 // telnet defaults to port 23
 Server server(23);
@@ -60,4 +60,4 @@ void loop() {
     // echo the bytes to the server as well:
     Serial.print(thisChar);
   }
-}
\ No newline at end of file
+}
diff --git a/libraries/Ethernet/examples/PachubeClient/PachubeClient.pde b/libraries/Ethernet/examples/PachubeClient/PachubeClient.pde
index fe94541e127..687fa437e65 100644
--- a/libraries/Ethernet/examples/PachubeClient/PachubeClient.pde
+++ b/libraries/Ethernet/examples/PachubeClient/PachubeClient.pde
@@ -23,20 +23,13 @@
 #include <Ethernet.h>
 
 // assign a MAC address for the ethernet controller.
+// Newer Ethernet shields have a MAC address printed on a sticker on the shield
 // fill in your address here:
 byte mac[] = { 
   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
-// assign an IP address for the controller:
-byte ip[] = { 
-  192,169,1,20 };
-byte gateway[] = {
-  192,168,1,1};	
-byte subnet[] = { 
-  255, 255, 255, 0 };
 
 //  The address of the server you want to connect to (pachube.com):
-byte server[] = { 
-  209,40,205,190 }; 
+IPAddress server(209,40,205,190); 
 
 // initialize the library instance:
 Client client(server, 80);
@@ -46,9 +39,15 @@ boolean lastConnected = false;      // state of the connection last time through
 const int postingInterval = 10000;  //delay between updates to Pachube.com
 
 void setup() {
-  // start the ethernet connection and serial port:
-  Ethernet.begin(mac, ip);
+  // start serial port:
   Serial.begin(9600);
+  // start the Ethernet connection:
+  if (Ethernet.begin(mac) == 0) {
+    Serial.println("Failed to configure Ethernet using DHCP");
+    // no point in carrying on, so do nothing forevermore:
+    for(;;)
+      ;
+  }
   // give the ethernet module time to boot up:
   delay(1000);
 }
diff --git a/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.pde b/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.pde
index 225823ac16f..0db6e219a38 100644
--- a/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.pde
+++ b/libraries/Ethernet/examples/PachubeClientString/PachubeClientString.pde
@@ -29,16 +29,12 @@
 byte mac[] = { 
   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED};
 // assign an IP address for the controller:
-byte ip[] = { 
-  192,169,1,20 };
-byte gateway[] = {
-  192,168,1,1};	
-byte subnet[] = { 
-  255, 255, 255, 0 };
+IPAddress ip(192,169,1,20);
+IPAddress gateway(192,168,1,1);	
+IPAddress subnet(255, 255, 255, 0);
 
 //  The address of the server you want to connect to (pachube.com):
-byte server[] = { 
-  209,40,205,190 }; 
+IPAddress server(209,40,205,190); 
 
 // initialize the library instance:
 Client client(server, 80);
diff --git a/libraries/Ethernet/examples/TelnetClient/TelnetClient.pde b/libraries/Ethernet/examples/TelnetClient/TelnetClient.pde
index aca1fa9adc5..95756d07692 100644
--- a/libraries/Ethernet/examples/TelnetClient/TelnetClient.pde
+++ b/libraries/Ethernet/examples/TelnetClient/TelnetClient.pde
@@ -24,12 +24,10 @@
 // The IP address will be dependent on your local network:
 byte mac[] = {  
   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
-byte ip[] = { 
-  192,168,1,177 };
+IPAddress ip(192,168,1,177);
 
 // Enter the IP address of the server you're connecting to:
-byte server[] = { 
-  1,1,1,1 }; 
+IPAddress server(1,1,1,1); 
 
 // Initialize the Ethernet client library
 // with the IP address and port of the server 
diff --git a/libraries/Ethernet/examples/UDPSendReceiveString/UDPSendReceiveString.pde b/libraries/Ethernet/examples/UDPSendReceiveString/UDPSendReceiveString.pde
index f27290f5424..081d6911485 100644
--- a/libraries/Ethernet/examples/UDPSendReceiveString/UDPSendReceiveString.pde
+++ b/libraries/Ethernet/examples/UDPSendReceiveString/UDPSendReceiveString.pde
@@ -22,15 +22,10 @@
 // The IP address will be dependent on your local network:
 byte mac[] = {  
   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
-byte ip[] = { 
-  192,168,1,177 };
+IPAddress ip(192, 168, 1, 177);
 
 unsigned int localPort = 8888;      // local port to listen on
 
-// the next two variables are set when a packet is received
-byte remoteIp[4];        // holds received packet's originating IP
-unsigned int remotePort; // holds received packet's originating port
-
 // buffers for receiving and sending data
 char packetBuffer[UDP_TX_PACKET_MAX_SIZE]; //buffer to hold incoming packet,
 char  ReplyBuffer[] = "acknowledged";       // a string to send back
@@ -48,19 +43,33 @@ void setup() {
 
 void loop() {
   // if there's data available, read a packet
-  int packetSize = Udp.available(); // note that this includes the UDP header
+  int packetSize = Udp.parsePacket();
   if(packetSize)
   {
-    packetSize = packetSize - 8;      // subtract the 8 byte header
     Serial.print("Received packet of size ");
     Serial.println(packetSize);
-
-    // read the packet into packetBufffer and get the senders IP addr and port number
-    Udp.readPacket(packetBuffer,UDP_TX_PACKET_MAX_SIZE, remoteIp, remotePort);
+    Serial.print("From ");
+    IPAddress remote = Udp.remoteIP();
+    for (int i =0; i < 4; i++)
+    {
+      Serial.print(remote[i], DEC);
+      if (i < 3)
+      {
+        Serial.print(".");
+      }
+    }
+    Serial.print(", port ");
+    Serial.println(Udp.remotePort());
+
+    // read the packet into packetBufffer
+    Udp.read(packetBuffer,UDP_TX_PACKET_MAX_SIZE);
     Serial.println("Contents:");
     Serial.println(packetBuffer);
 
-    Udp.sendPacket( ReplyBuffer, remoteIp, remotePort);
+    // send a reply, to the IP address and port that sent us the packet we received
+    Udp.beginPacket(Udp.remoteIP(), Udp.remotePort());
+    Udp.write(ReplyBuffer);
+    Udp.endPacket();
   }
   delay(10);
 }
diff --git a/libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.pde b/libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.pde
index 22bc754c566..7c2d3ea9e97 100644
--- a/libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.pde
+++ b/libraries/Ethernet/examples/UdpNtpClient/UdpNtpClient.pde
@@ -20,18 +20,14 @@
 #include <Ethernet.h>
 #include <Udp.h>
 
-// Enter a MAC address and IP address for your controller below.
-// The IP address will be dependent on your local network:
+// Enter a MAC address for your controller below.
+// Newer Ethernet shields have a MAC address printed on a sticker on the shield
 byte mac[] = {  
   0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
-byte ip[] = { 
-  192,168,1,177 };
-
 
 unsigned int localPort = 8888;      // local port to listen for UDP packets
 
-byte timeServer[] = { 
-  192, 43, 244, 18}; // time.nist.gov NTP server
+IPAddress timeServer(192, 43, 244, 18); // time.nist.gov NTP server
 
 const int NTP_PACKET_SIZE= 48; // NTP time stamp is in the first 48 bytes of the message
 
@@ -42,11 +38,16 @@ UDP Udp;
 
 void setup() 
 {
+  Serial.begin(9600);
+
   // start Ethernet and UDP
-  Ethernet.begin(mac,ip);
+  if (Ethernet.begin(mac) == 0) {
+    Serial.println("Failed to configure Ethernet using DHCP");
+    // no point in carrying on, so do nothing forevermore:
+    for(;;)
+      ;
+  }
   Udp.begin(localPort);
-
-  Serial.begin(9600);
 }
 
 void loop()
@@ -55,8 +56,9 @@ void loop()
 
     // wait to see if a reply is available
   delay(1000);  
-  if ( Udp.available() ) {  
-    Udp.readPacket(packetBuffer,NTP_PACKET_SIZE);  // read the packet into the buffer
+  if ( Udp.parsePacket() ) {  
+    // We've received a packet, read the data from it
+    Udp.read(packetBuffer,NTP_PACKET_SIZE);  // read the packet into the buffer
 
     //the timestamp starts at byte 40 of the received packet and is four bytes,
     // or two words, long. First, esxtract the two words:
@@ -100,7 +102,7 @@ void loop()
 }
 
 // send an NTP request to the time server at the given address 
-unsigned long sendNTPpacket(byte *address)
+unsigned long sendNTPpacket(IPAddress& address)
 {
   // set all bytes in the buffer to 0
   memset(packetBuffer, 0, NTP_PACKET_SIZE); 
@@ -118,7 +120,9 @@ unsigned long sendNTPpacket(byte *address)
 
   // all NTP fields have been given values, now
   // you can send a packet requesting a timestamp: 		   
-  Udp.sendPacket( packetBuffer,NTP_PACKET_SIZE,  address, 123); //NTP requests are to port 123
+  Udp.beginPacket(address, 123); //NTP requests are to port 123
+  Udp.write(packetBuffer,NTP_PACKET_SIZE);
+  Udp.endPacket(); 
 }
 
 
diff --git a/libraries/Ethernet/examples/WebClient/WebClient.pde b/libraries/Ethernet/examples/WebClient/WebClient.pde
index a2d3503115e..74d34e0cecd 100644
--- a/libraries/Ethernet/examples/WebClient/WebClient.pde
+++ b/libraries/Ethernet/examples/WebClient/WebClient.pde
@@ -15,11 +15,10 @@
 #include <SPI.h>
 #include <Ethernet.h>
 
-// Enter a MAC address and IP address for your controller below.
-// The IP address will be dependent on your local network:
+// Enter a MAC address for your controller below.
+// Newer Ethernet shields have a MAC address printed on a sticker on the shield
 byte mac[] = {  0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
-byte ip[] = { 192,168,1,177 };
-byte server[] = { 173,194,33,104 }; // Google
+IPAddress server(173,194,33,104); // Google
 
 // Initialize the Ethernet client library
 // with the IP address and port of the server 
@@ -27,10 +26,15 @@ byte server[] = { 173,194,33,104 }; // Google
 Client client(server, 80);
 
 void setup() {
-  // start the Ethernet connection:
-  Ethernet.begin(mac, ip);
   // start the serial library:
   Serial.begin(9600);
+  // start the Ethernet connection:
+  if (Ethernet.begin(mac) == 0) {
+    Serial.println("Failed to configure Ethernet using DHCP");
+    // no point in carrying on, so do nothing forevermore:
+    for(;;)
+      ;
+  }
   // give the Ethernet shield a second to initialize:
   delay(1000);
   Serial.println("connecting...");
diff --git a/libraries/Ethernet/examples/WebServer/WebServer.pde b/libraries/Ethernet/examples/WebServer/WebServer.pde
index 77bcb204ed8..c69a56a4040 100644
--- a/libraries/Ethernet/examples/WebServer/WebServer.pde
+++ b/libraries/Ethernet/examples/WebServer/WebServer.pde
@@ -21,7 +21,7 @@
 // Enter a MAC address and IP address for your controller below.
 // The IP address will be dependent on your local network:
 byte mac[] = { 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED };
-byte ip[] = { 192,168,1, 177 };
+IPAddress ip(192,168,1, 177);
 
 // Initialize the Ethernet server library
 // with the IP address and port you want to use 
@@ -79,4 +79,4 @@ void loop()
     // close the connection:
     client.stop();
   }
-}
\ No newline at end of file
+}
diff --git a/libraries/Ethernet/keywords.txt b/libraries/Ethernet/keywords.txt
index ebc57936394..7fdcedf090e 100644
--- a/libraries/Ethernet/keywords.txt
+++ b/libraries/Ethernet/keywords.txt
@@ -9,6 +9,7 @@
 Ethernet	KEYWORD1
 Client	KEYWORD1
 Server	KEYWORD1
+IPAddress	KEYWORD1
 
 #######################################
 # Methods and Functions (KEYWORD2)
@@ -19,10 +20,16 @@ connect	KEYWORD2
 write	KEYWORD2
 available	KEYWORD2
 read	KEYWORD2
+peek	KEYWORD2
 flush	KEYWORD2
 stop	KEYWORD2
 connected	KEYWORD2
 begin	KEYWORD2
+beginPacket	KEYWORD2
+endPacket	KEYWORD2
+parsePacket	KEYWORD2
+remoteIP	KEYWORD2
+remotePort	KEYWORD2
 
 #######################################
 # Constants (LITERAL1)
diff --git a/libraries/Ethernet/util.h b/libraries/Ethernet/util.h
new file mode 100644
index 00000000000..220011b8fd4
--- /dev/null
+++ b/libraries/Ethernet/util.h
@@ -0,0 +1,13 @@
+#ifndef UTIL_H
+#define UTIL_H
+
+#define htons(x) ( (x)<<8 | ((x)>>8)&0xFF )
+#define ntohs(x) htons(x)
+
+#define htonl(x) ( ((x)<<24 & 0xFF000000UL) | \
+                   ((x)<< 8 & 0x00FF0000UL) | \
+                   ((x)>> 8 & 0x0000FF00UL) | \
+                   ((x)>>24 & 0x000000FFUL) )
+#define ntohl(x) htonl(x)
+
+#endif
diff --git a/libraries/Ethernet/utility/socket.cpp b/libraries/Ethernet/utility/socket.cpp
index cad54a5e379..487584511e4 100644
--- a/libraries/Ethernet/utility/socket.cpp
+++ b/libraries/Ethernet/utility/socket.cpp
@@ -344,3 +344,58 @@ uint16_t igmpsend(SOCKET s, const uint8_t * buf, uint16_t len)
   return ret;
 }
 
+uint16_t bufferData(SOCKET s, uint16_t offset, const uint8_t* buf, uint16_t len)
+{
+  uint16_t ret =0;
+  if (len > W5100.getTXFreeSize(s))
+  {
+    ret = W5100.getTXFreeSize(s); // check size not to exceed MAX size.
+  }
+  else
+  {
+    ret = len;
+  }
+  W5100.send_data_processing_offset(s, offset, buf, ret);
+  return ret;
+}
+
+int startUDP(SOCKET s, uint8_t* addr, uint16_t port)
+{
+  if
+    (
+     ((addr[0] == 0x00) && (addr[1] == 0x00) && (addr[2] == 0x00) && (addr[3] == 0x00)) ||
+     ((port == 0x00))
+    ) 
+  {
+    return 0;
+  }
+  else
+  {
+    W5100.writeSnDIPR(s, addr);
+    W5100.writeSnDPORT(s, port);
+    return 1;
+  }
+}
+
+int sendUDP(SOCKET s)
+{
+  W5100.execCmdSn(s, Sock_SEND);
+		
+  /* +2008.01 bj */
+  while ( (W5100.readSnIR(s) & SnIR::SEND_OK) != SnIR::SEND_OK ) 
+  {
+    if (W5100.readSnIR(s) & SnIR::TIMEOUT)
+    {
+      /* +2008.01 [bj]: clear interrupt */
+      W5100.writeSnIR(s, (SnIR::SEND_OK|SnIR::TIMEOUT));
+      return 0;
+    }
+  }
+
+  /* +2008.01 bj */	
+  W5100.writeSnIR(s, SnIR::SEND_OK);
+
+  /* Sent ok */
+  return 1;
+}
+
diff --git a/libraries/Ethernet/utility/socket.h b/libraries/Ethernet/utility/socket.h
index 48e2d877b73..37ea93f3d75 100755
--- a/libraries/Ethernet/utility/socket.h
+++ b/libraries/Ethernet/utility/socket.h
@@ -16,5 +16,26 @@ extern uint16_t recvfrom(SOCKET s, uint8_t * buf, uint16_t len, uint8_t * addr,
 
 extern uint16_t igmpsend(SOCKET s, const uint8_t * buf, uint16_t len);
 
+// Functions to allow buffered UDP send (i.e. where the UDP datagram is built up over a
+// number of calls before being sent
+/*
+  @brief This function sets up a UDP datagram, the data for which will be provided by one
+  or more calls to bufferData and then finally sent with sendUDP.
+  @return 1 if the datagram was successfully set up, or 0 if there was an error
+*/
+extern int startUDP(SOCKET s, uint8_t* addr, uint16_t port);
+/*
+  @brief This function copies up to len bytes of data from buf into a UDP datagram to be
+  sent later by sendUDP.  Allows datagrams to be built up from a series of bufferData calls.
+  @return Number of bytes successfully buffered
+*/
+uint16_t bufferData(SOCKET s, uint16_t offset, const uint8_t* buf, uint16_t len);
+/*
+  @brief Send a UDP datagram built up from a sequence of startUDP followed by one or more
+  calls to bufferData.
+  @return 1 if the datagram was successfully sent, or 0 if there was an error
+*/
+int sendUDP(SOCKET s);
+
 #endif
 /* _SOCKET_H_ */
diff --git a/libraries/Ethernet/utility/w5100.cpp b/libraries/Ethernet/utility/w5100.cpp
index aaf3071f7d0..aafabaeec7b 100644
--- a/libraries/Ethernet/utility/w5100.cpp
+++ b/libraries/Ethernet/utility/w5100.cpp
@@ -65,10 +65,16 @@ uint16_t W5100Class::getRXReceivedSize(SOCKET s)
 }
 
 
-void W5100Class::send_data_processing(SOCKET s, uint8_t *data, uint16_t len)
+void W5100Class::send_data_processing(SOCKET s, const uint8_t *data, uint16_t len)
 {
-  uint16_t ptr = readSnTX_WR(s);
+  // This is same as having no offset in a call to send_data_processing_offset
+  send_data_processing_offset(s, 0, data, len);
+}
 
+void W5100Class::send_data_processing_offset(SOCKET s, uint16_t data_offset, const uint8_t *data, uint16_t len)
+{
+  uint16_t ptr = readSnTX_WR(s);
+  ptr += data_offset;
   uint16_t offset = ptr & SMASK;
   uint16_t dstAddr = offset + SBASE[s];
 
@@ -132,7 +138,7 @@ uint8_t W5100Class::write(uint16_t _addr, uint8_t _data)
   return 1;
 }
 
-uint16_t W5100Class::write(uint16_t _addr, uint8_t *_buf, uint16_t _len)
+uint16_t W5100Class::write(uint16_t _addr, const uint8_t *_buf, uint16_t _len)
 {
   for (int i=0; i<_len; i++)
   {
diff --git a/libraries/Ethernet/utility/w5100.h b/libraries/Ethernet/utility/w5100.h
index 118e5d80d43..9872c7ccb09 100755
--- a/libraries/Ethernet/utility/w5100.h
+++ b/libraries/Ethernet/utility/w5100.h
@@ -146,7 +146,19 @@ class W5100Class {
    * This function read the Tx write pointer register and after copy the data in buffer update the Tx write pointer
    * register. User should read upper byte first and lower byte later to get proper value.
    */
-  void send_data_processing(SOCKET s, uint8_t *data, uint16_t len);
+  void send_data_processing(SOCKET s, const uint8_t *data, uint16_t len);
+  /**
+   * @brief A copy of send_data_processing that uses the provided ptr for the
+   *        write offset.  Only needed for the "streaming" UDP API, where
+   *        a single UDP packet is built up over a number of calls to
+   *        send_data_processing_ptr, because TX_WR doesn't seem to get updated
+   *        correctly in those scenarios
+   * @param ptr value to use in place of TX_WR.  If 0, then the value is read
+   *        in from TX_WR
+   * @return New value for ptr, to be used in the next call
+   */
+// FIXME Update documentation
+  void send_data_processing_offset(SOCKET s, uint16_t data_offset, const uint8_t *data, uint16_t len);
 
   /**
    * @brief	This function is being called by recv() also.
@@ -182,7 +194,7 @@ class W5100Class {
   // ---------------
 private:
   static uint8_t write(uint16_t _addr, uint8_t _data);
-  static uint16_t write(uint16_t addr, uint8_t *buf, uint16_t len);
+  static uint16_t write(uint16_t addr, const uint8_t *buf, uint16_t len);
   static uint8_t read(uint16_t addr);
   static uint16_t read(uint16_t addr, uint8_t *buf, uint16_t len);