diff --git a/Ping/Ping.c b/Ping/Ping.c
index 97cd0f1..7d92881 100644
--- a/Ping/Ping.c
+++ b/Ping/Ping.c
@@ -63,6 +63,48 @@ SHELL_VAR_CHECK_ITEM  PingCheckList[] = {
   }
 };
 
+//
+// All the supported IP4 maskes in host byte order.
+//
+IP4_ADDR  gIp4AllMasks[IP4_MASK_NUM] = {
+  0x00000000,
+  0x80000000,
+  0xC0000000,
+  0xE0000000,
+  0xF0000000,
+  0xF8000000,
+  0xFC000000,
+  0xFE000000,
+
+  0xFF000000,
+  0xFF800000,
+  0xFFC00000,
+  0xFFE00000,
+  0xFFF00000,
+  0xFFF80000,
+  0xFFFC0000,
+  0xFFFE0000,
+
+  0xFFFF0000,
+  0xFFFF8000,
+  0xFFFFC000,
+  0xFFFFE000,
+  0xFFFFF000,
+  0xFFFFF800,
+  0xFFFFFC00,
+  0xFFFFFE00,
+
+  0xFFFFFF00,
+  0xFFFFFF80,
+  0xFFFFFFC0,
+  0xFFFFFFE0,
+  0xFFFFFFF0,
+  0xFFFFFFF8,
+  0xFFFFFFFC,
+  0xFFFFFFFE,
+  0xFFFFFFFF,
+};
+
 EFI_IPv4_ADDRESS  DestinationIp;
 EFI_LIST_ENTRY    IcmpTxTimeoutList;
 UINT16            Identifier;
@@ -520,6 +562,106 @@ Routine Description:
   }
 }
 
+STATIC
+INTN
+EFIAPI
+NetGetIpClass (
+  IN IP4_ADDR               Addr
+  )
+/*++
+
+Routine Description:
+
+  Return the class of the IP address, such as class A, B, C.
+  Addr is in host byte order.
+
+  The address of class A  starts with 0.
+  If the address belong to class A, return IP4_ADDR_CLASSA.
+  The address of class B  starts with 10.
+  If the address belong to class B, return IP4_ADDR_CLASSB.
+  The address of class C  starts with 110.
+  If the address belong to class C, return IP4_ADDR_CLASSC.
+  The address of class D  starts with 1110.
+  If the address belong to class D, return IP4_ADDR_CLASSD.
+  The address of class E  starts with 1111.
+  If the address belong to class E, return IP4_ADDR_CLASSE.
+
+Arguments:
+
+  Addr - The address to get the class from.
+
+Returns:
+
+  IP address class, such as IP4_ADDR_CLASSA.
+
+--*/
+{
+  UINT8                     ByteOne;
+
+  ByteOne = (UINT8) (Addr >> 24);
+
+  if ((ByteOne & 0x80) == 0) {
+    return IP4_ADDR_CLASSA;
+
+  } else if ((ByteOne & 0xC0) == 0x80) {
+    return IP4_ADDR_CLASSB;
+
+  } else if ((ByteOne & 0xE0) == 0xC0) {
+    return IP4_ADDR_CLASSC;
+
+  } else if ((ByteOne & 0xF0) == 0xE0) {
+    return IP4_ADDR_CLASSD;
+
+  } else {
+    return IP4_ADDR_CLASSE;
+
+  }
+}
+
+STATIC
+BOOLEAN
+EFIAPI
+NetIp4IsUnicast (
+  IN IP4_ADDR               Ip,
+  IN IP4_ADDR               NetMask
+  )
+/*++
+
+Routine Description:
+
+  Check whether the IP is a valid unicast address according to the netmask.
+  If NetMask is zero, use the IP address's class to get the default mask.
+
+Arguments:
+
+  Ip      - The IP to check against.
+  NetMask - The mask of the IP.
+
+Returns:
+
+  TRUE if IP is a valid unicast address on the network, otherwise FALSE.
+
+--*/
+{
+  INTN                      Class;
+
+  Class = NetGetIpClass (Ip);
+
+  if ((Ip == 0) || (Class >= IP4_ADDR_CLASSD)) {
+    return FALSE;
+  }
+
+  if (NetMask == 0) {
+    NetMask = gIp4AllMasks[Class << 3];
+  }
+
+  if (((Ip &~NetMask) == ~NetMask) || ((Ip &~NetMask) == 0)) {
+    return FALSE;
+  }
+
+  return TRUE;
+}
+
 STATIC
 VOID
 HandleIcmpEchoReply (
@@ -555,8 +697,9 @@ Routine Description:
     //
     return;
   }
-
-  if (!EFI_IP4_EQUAL (RxData->Header->SourceAddress, DestinationIp)) {
+  
+  if (NetIp4IsUnicast (NTOHL (EFI_IP4 (DestinationIp)), 0) && 
+      !EFI_IP4_EQUAL (RxData->Header->SourceAddress, DestinationIp)) {
     //
     // The source address of this ICMP packet is different from the DestinationIp.
     //
diff --git a/Ping/Ping.h b/Ping/Ping.h
index 8f6727e..7867caf 100644
--- a/Ping/Ping.h
+++ b/Ping/Ping.h
@@ -1,6 +1,6 @@
 /*++
 
-Copyright (c) 2006, Intel Corporation                                                         
+Copyright (c) 2006 - 2010, Intel Corporation                                              
 All rights reserved. This program and the accompanying materials                          
 are licensed and made available under the terms and conditions of the BSD License         
 which accompanies this distribution. The full text of the license may be found at         
@@ -38,8 +38,28 @@ Revision History
 
 #define PING_MAX_BUFFER_SIZE    32768
 
+//
+// The address classification
+//
+#define  IP4_ADDR_CLASSA        1
+#define  IP4_ADDR_CLASSB        2
+#define  IP4_ADDR_CLASSC        3
+#define  IP4_ADDR_CLASSD        4
+#define  IP4_ADDR_CLASSE        5
+
+#define  IP4_MASK_NUM           33
+
+typedef UINT32 IP4_ADDR;
+
 #define EFI_IP4_EQUAL(Ip1, Ip2) (CompareMem (&(Ip1), &(Ip2), sizeof (EFI_IPv4_ADDRESS)) == 0)
 
+#define EFI_IP4(EfiIpAddr)      (*(IP4_ADDR *) ((EfiIpAddr).Addr))
+
+#define NTOHL(x) (UINT32)((((UINT32) (x) & 0xff)     << 24) | \
+                          (((UINT32) (x) & 0xff00)   << 8)  | \
+                          (((UINT32) (x) & 0xff0000) >> 8)  | \
+                          (((UINT32) (x) & 0xff000000) >> 24))
+
 #pragma pack(1)
 typedef struct _EFI_ICMP_ECHO_REQUEST {
   UINT8   Type;