diff --git a/src/core/thread/mle.cpp b/src/core/thread/mle.cpp
index 204b5086d..9127eaf06 100644
--- a/src/core/thread/mle.cpp
+++ b/src/core/thread/mle.cpp
@@ -2026,6 +2026,7 @@ ThreadError Mle::HandleChildUpdateResponse(const Message &aMessage, const Ip6::M
     LeaderDataTlv leaderData;
     SourceAddressTlv sourceAddress;
     TimeoutTlv timeout;
+    NetworkDataTlv networkData;
     uint8_t tlvs[] = {Tlv::kNetworkData};
 
     otLogInfoMle("Received Child Update Response\n");
@@ -2061,11 +2062,6 @@ ThreadError Mle::HandleChildUpdateResponse(const Message &aMessage, const Ip6::M
         SuccessOrExit(error = Tlv::GetTlv(aMessage, Tlv::kLeaderData, sizeof(leaderData), leaderData));
         VerifyOrExit(leaderData.IsValid(), error = kThreadError_Parse);
 
-        if (static_cast<int8_t>(leaderData.GetDataVersion() - mNetworkData.GetVersion()) > 0)
-        {
-            SendDataRequest(aMessageInfo.GetPeerAddr(), tlvs, sizeof(tlvs));
-        }
-
         // Source Address
         SuccessOrExit(error = Tlv::GetTlv(aMessage, Tlv::kSourceAddress, sizeof(sourceAddress), sourceAddress));
         VerifyOrExit(sourceAddress.IsValid(), error = kThreadError_Parse);
@@ -2083,7 +2079,16 @@ ThreadError Mle::HandleChildUpdateResponse(const Message &aMessage, const Ip6::M
             mTimeout = timeout.GetTimeout();
         }
 
-        if ((mode.GetMode() & ModeTlv::kModeRxOnWhenIdle) == 0)
+        // Network Data optional
+        if (Tlv::GetTlv(aMessage, Tlv::kNetworkData, sizeof(networkData), networkData) == kThreadError_None)
+        {
+            VerifyOrExit(networkData.IsValid(), error = kThreadError_Parse);
+            mNetworkData.SetNetworkData(leaderData.GetDataVersion(), leaderData.GetStableDataVersion(),
+                                        (mDeviceMode & ModeTlv::kModeFullNetworkData) == 0,
+                                        networkData.GetNetworkData(), networkData.GetLength());
+        }
+
+        if ((mDeviceMode & ModeTlv::kModeRxOnWhenIdle) == 0)
         {
             mMesh.SetPollPeriod(Timer::SecToMsec(mTimeout / kMaxChildKeepAliveAttempts));
             mMesh.SetRxOnWhenIdle(false);
@@ -2093,6 +2098,23 @@ ThreadError Mle::HandleChildUpdateResponse(const Message &aMessage, const Ip6::M
             mMesh.SetRxOnWhenIdle(true);
         }
 
+        if (mDeviceMode & ModeTlv::kModeFullNetworkData)
+        {
+            // full network data
+            if (leaderData.GetDataVersion() != mNetworkData.GetVersion())
+            {
+                SendDataRequest(aMessageInfo.GetPeerAddr(), tlvs, sizeof(tlvs));
+            }
+        }
+        else
+        {
+            // stable network data
+            if (leaderData.GetStableDataVersion() != mNetworkData.GetStableVersion())
+            {
+                SendDataRequest(aMessageInfo.GetPeerAddr(), tlvs, sizeof(tlvs));
+            }
+        }
+
         break;
 
     default:
diff --git a/src/core/thread/mle_router.cpp b/src/core/thread/mle_router.cpp
index 108f21222..459dfcd71 100644
--- a/src/core/thread/mle_router.cpp
+++ b/src/core/thread/mle_router.cpp
@@ -1982,6 +1982,8 @@ exit:
 
 ThreadError MleRouter::HandleChildUpdateRequest(const Message &aMessage, const Ip6::MessageInfo &aMessageInfo)
 {
+    static const uint8_t kMaxResponseTlvs = 8;
+
     ThreadError error = kThreadError_None;
     Mac::ExtAddress macAddr;
     ModeTlv mode;
@@ -1990,7 +1992,7 @@ ThreadError MleRouter::HandleChildUpdateRequest(const Message &aMessage, const I
     LeaderDataTlv leaderData;
     TimeoutTlv timeout;
     Child *child;
-    uint8_t tlvs[7];
+    uint8_t tlvs[kMaxResponseTlvs];
     uint8_t tlvslength = 0;
 
     otLogInfoMle("Received Child Update Request\n");
@@ -2038,13 +2040,29 @@ ThreadError MleRouter::HandleChildUpdateRequest(const Message &aMessage, const I
 
         if (child->mMode & ModeTlv::kModeFullNetworkData)
         {
+            // full network data
             child->mNetworkDataVersion = leaderData.GetDataVersion();
+
+            if (leaderData.GetDataVersion() != mNetworkData.GetVersion())
+            {
+                tlvs[tlvslength++] = Tlv::kNetworkData;
+            }
         }
         else
         {
+            // stable network data
             child->mNetworkDataVersion = leaderData.GetStableDataVersion();
+
+            if (leaderData.GetStableDataVersion() != mNetworkData.GetStableVersion())
+            {
+                tlvs[tlvslength++] = Tlv::kNetworkData;
+            }
         }
     }
+    else
+    {
+        tlvs[tlvslength++] = Tlv::kNetworkData;
+    }
 
     // Timeout
     if (Tlv::GetTlv(aMessage, Tlv::kTimeout, sizeof(timeout), timeout) == kThreadError_None)
@@ -2241,6 +2259,10 @@ ThreadError MleRouter::SendChildUpdateResponse(Child *aChild, const Ip6::Message
             SuccessOrExit(error = AppendMode(*message, aChild->mMode));
             break;
 
+        case Tlv::kNetworkData:
+            SuccessOrExit(error = AppendNetworkData(*message, (aChild->mMode & ModeTlv::kModeFullNetworkData) == 0));
+            break;
+
         case Tlv::kResponse:
             SuccessOrExit(error = AppendResponse(*message, aChallenge->GetChallenge(), aChallenge->GetLength()));
             break;