diff --git a/libraries/mbed/targets/cmsis/TARGET_NXP/TARGET_LPC176X/TOOLCHAIN_GCC_ARM/LPC1768.ld b/libraries/mbed/targets/cmsis/TARGET_NXP/TARGET_LPC176X/TOOLCHAIN_GCC_ARM/LPC1768.ld
index 9ad0af0be0..c4d3447dab 100644
--- a/libraries/mbed/targets/cmsis/TARGET_NXP/TARGET_LPC176X/TOOLCHAIN_GCC_ARM/LPC1768.ld
+++ b/libraries/mbed/targets/cmsis/TARGET_NXP/TARGET_LPC176X/TOOLCHAIN_GCC_ARM/LPC1768.ld
@@ -4,7 +4,7 @@
 MEMORY
 {
   FLASH (rx) : ORIGIN = 0x00000000, LENGTH = 512K
-  RAM (rwx) : ORIGIN = 0x100000C8, LENGTH = 0x7F38
+  RAM (rwx) : ORIGIN = 0x100000C8, LENGTH = (32K - 0xC8)
 
   USB_RAM(rwx) : ORIGIN = 0x2007C000, LENGTH = 16K
   ETH_RAM(rwx) : ORIGIN = 0x20080000, LENGTH = 16K
@@ -84,6 +84,7 @@ SECTIONS
     .data : AT (__etext)
     {
         __data_start__ = .;
+        Image$$RW_IRAM1$$Base = .;
         *(vtable)
         *(.data*)
 
@@ -120,6 +121,7 @@ SECTIONS
         *(.bss*)
         *(COMMON)
         __bss_end__ = .;
+        Image$$RW_IRAM1$$ZI$$Limit = . ;
     } > RAM
     
     .heap :
@@ -146,4 +148,23 @@ SECTIONS
     
     /* Check if data + heap + stack exceeds RAM limit */
     ASSERT(__StackLimit >= __HeapLimit, "region RAM overflowed with stack")
+
+
+    /* Code can explicitly ask for data to be 
+       placed in these higher RAM banks where
+       they will be left uninitialized. 
+    */
+    .AHBSRAM0 (NOLOAD):
+    {
+        Image$$RW_IRAM2$$Base = . ;
+        *(AHBSRAM0)
+        Image$$RW_IRAM2$$ZI$$Limit = .;
+    } > USB_RAM
+
+    .AHBSRAM1 (NOLOAD):
+    {
+        Image$$RW_IRAM3$$Base = . ;
+        *(AHBSRAM1)
+        Image$$RW_IRAM3$$ZI$$Limit = .;
+    } > ETH_RAM
 }
diff --git a/libraries/net/eth/lwip-eth/arch/lpc17_emac.c b/libraries/net/eth/lwip-eth/arch/lpc17_emac.c
index 0d06464ab7..06772f48f1 100644
--- a/libraries/net/eth/lwip-eth/arch/lpc17_emac.c
+++ b/libraries/net/eth/lwip-eth/arch/lpc17_emac.c
@@ -618,14 +618,14 @@ static err_t lpc_low_level_output(struct netif *netif, struct pbuf *p)
 	struct lpc_enetdata *lpc_enetif = netif->state;
 	struct pbuf *q;
 	u8_t *dst;
-    u32_t idx;
+    u32_t idx, notdmasafe = 0;
 	struct pbuf *np;
-	u32_t dn, notdmasafe = 0;
+	s32_t dn;
 
 	/* Zero-copy TX buffers may be fragmented across mutliple payload
 	   chains. Determine the number of descriptors needed for the
 	   transfer. The pbuf chaining can be a mess! */
-	dn = (u32_t) pbuf_clen(p);
+	dn = (s32_t) pbuf_clen(p);
 
 	/* Test to make sure packet addresses are DMA safe. A DMA safe
 	   address is once that uses external memory or periphheral RAM.
diff --git a/libraries/net/eth/lwip-eth/arch/lpc_phy_dp83848.c b/libraries/net/eth/lwip-eth/arch/lpc_phy_dp83848.c
index 76ffc0cf9a..eca6d97338 100644
--- a/libraries/net/eth/lwip-eth/arch/lpc_phy_dp83848.c
+++ b/libraries/net/eth/lwip-eth/arch/lpc_phy_dp83848.c
@@ -228,9 +228,9 @@ err_t lpc_phy_init(struct netif *netif, int rmii)
 	u32_t tmp;
 	s32_t i;
 
-	physts.phy_speed_100mbs = olddphysts.phy_speed_100mbs = 2;
-	physts.phy_full_duplex = olddphysts.phy_full_duplex = 2;
-	physts.phy_link_active = olddphysts.phy_link_active = 2;
+	physts.phy_speed_100mbs = olddphysts.phy_speed_100mbs = 0;
+	physts.phy_full_duplex = olddphysts.phy_full_duplex = 0;
+	physts.phy_link_active = olddphysts.phy_link_active = 0;
 	phyustate = 0;
 
 	/* Only first read and write are checked for failure */
diff --git a/libraries/net/lwip/Socket/TCPSocketConnection.cpp b/libraries/net/lwip/Socket/TCPSocketConnection.cpp
index d84dc9c6b3..b853304099 100644
--- a/libraries/net/lwip/Socket/TCPSocketConnection.cpp
+++ b/libraries/net/lwip/Socket/TCPSocketConnection.cpp
@@ -66,7 +66,7 @@ int TCPSocketConnection::send_all(char* data, int length) {
     if ((_sock_fd < 0) || !_is_connected)
         return -1;
     
-    size_t writtenLen = 0;
+    int writtenLen = 0;
     TimeInterval timeout(_timeout);
     while (writtenLen < length) {
         if (!_blocking) {
@@ -110,7 +110,7 @@ int TCPSocketConnection::receive_all(char* data, int length) {
     if ((_sock_fd < 0) || !_is_connected)
         return -1;
     
-    size_t readLen = 0;
+    int readLen = 0;
     TimeInterval timeout(_timeout);
     while (readLen < length) {
         if (!_blocking) {
diff --git a/libraries/net/lwip/lwip-sys/arch/cc.h b/libraries/net/lwip/lwip-sys/arch/cc.h
index f9b8e22385..394635a612 100644
--- a/libraries/net/lwip/lwip-sys/arch/cc.h
+++ b/libraries/net/lwip/lwip-sys/arch/cc.h
@@ -80,7 +80,6 @@ typedef uintptr_t          mem_ptr_t;
     #define PACK_STRUCT_END
     #define PACK_STRUCT_FIELD(fld) fld
     #define ALIGNED(n)  __attribute__((aligned (n)))
-    #define ALIGNED(n)  __align(n)
 #endif 
 
 /* Used with IP headers only */
diff --git a/libraries/net/lwip/lwip/core/dhcp.c b/libraries/net/lwip/lwip/core/dhcp.c
index 81b4be271e..03c0c62384 100644
--- a/libraries/net/lwip/lwip/core/dhcp.c
+++ b/libraries/net/lwip/lwip/core/dhcp.c
@@ -564,7 +564,7 @@ dhcp_handle_ack(struct netif *netif)
 #if LWIP_DNS
   /* DNS servers */
   n = 0;
-  while(dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n) && (n < DNS_MAX_SERVERS)) {
+  while((n < DNS_MAX_SERVERS) && dhcp_option_given(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)) {
     ip_addr_t dns_addr;
     ip4_addr_set_u32(&dns_addr, htonl(dhcp_get_option_value(dhcp, DHCP_OPTION_IDX_DNS_SERVER + n)));
     dns_setserver(n, &dns_addr);
@@ -975,7 +975,7 @@ dhcp_bind(struct netif *netif)
 
   ip_addr_copy(gw_addr, dhcp->offered_gw_addr);
   /* gateway address not given? */
-  if (ip_addr_isany(&gw_addr)) {
+  if (gw_addr.addr == IPADDR_ANY) {
     /* copy network address */
     ip_addr_get_network(&gw_addr, &dhcp->offered_ip_addr, &sn_mask);
     /* use first host address on network as gateway */
@@ -1678,9 +1678,13 @@ dhcp_create_msg(struct netif *netif, struct dhcp *dhcp, u8_t message_type)
   ip_addr_set_zero(&dhcp->msg_out->yiaddr);
   ip_addr_set_zero(&dhcp->msg_out->siaddr);
   ip_addr_set_zero(&dhcp->msg_out->giaddr);
-  for (i = 0; i < DHCP_CHADDR_LEN; i++) {
-    /* copy netif hardware address, pad with zeroes */
-    dhcp->msg_out->chaddr[i] = (i < netif->hwaddr_len) ? netif->hwaddr[i] : 0/* pad byte*/;
+  for (i = 0; i < netif->hwaddr_len; i++) {
+    /* copy netif hardware address */
+    dhcp->msg_out->chaddr[i] = netif->hwaddr[i];
+  }
+  for ( ; i < DHCP_CHADDR_LEN; i++) {
+    /* ... pad rest with zeroes */
+    dhcp->msg_out->chaddr[i] = 0;
   }
   for (i = 0; i < DHCP_SNAME_LEN; i++) {
     dhcp->msg_out->sname[i] = 0;
diff --git a/libraries/net/lwip/lwip/core/ipv4/ip.c b/libraries/net/lwip/lwip/core/ipv4/ip.c
index 6f248716b6..56843273d1 100644
--- a/libraries/net/lwip/lwip/core/ipv4/ip.c
+++ b/libraries/net/lwip/lwip/core/ipv4/ip.c
@@ -400,7 +400,7 @@ ip_input(struct pbuf *p, struct netif *inp)
   /* broadcast or multicast packet source address? Compliant with RFC 1122: 3.2.1.3 */
 #if IP_ACCEPT_LINK_LAYER_ADDRESSING
   /* DHCP servers need 0.0.0.0 to be allowed as source address (RFC 1.1.2.2: 3.2.1.3/a) */
-  if (check_ip_src && !ip_addr_isany(&current_iphdr_src))
+  if (check_ip_src && current_iphdr_src.addr != IPADDR_ANY)
 #endif /* IP_ACCEPT_LINK_LAYER_ADDRESSING */
   {  if ((ip_addr_isbroadcast(&current_iphdr_src, inp)) ||
          (ip_addr_ismulticast(&current_iphdr_src))) {