diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 090c7444c1..8c1f198252 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -1813,14 +1813,11 @@ public class ConnectivityService extends IConnectivityManager.Stub
     private void updateMtu(LinkProperties newLp, LinkProperties oldLp) {
         final String iface = newLp.getInterfaceName();
         final int mtu = newLp.getMtu();
-        if (oldLp == null && mtu == 0) {
-            // Silently ignore unset MTU value.
-            return;
-        }
         if (oldLp != null && newLp.isIdenticalMtu(oldLp)) {
             if (VDBG) log("identical MTU - not setting");
             return;
         }
+
         if (LinkProperties.isValidMtu(mtu, newLp.hasGlobalIPv6Address()) == false) {
             if (mtu != 0) loge("Unexpected mtu value: " + mtu + ", " + iface);
             return;
@@ -2266,19 +2263,11 @@ public class ConnectivityService extends IConnectivityManager.Stub
                     synchronized (mNetworkForNetId) {
                         nai = mNetworkForNetId.get(netId);
                     }
-                    // If captive portal status has changed, update capabilities or disconnect.
+                    // If captive portal status has changed, update capabilities.
                     if (nai != null && (visible != nai.lastCaptivePortalDetected)) {
                         final int oldScore = nai.getCurrentScore();
                         nai.lastCaptivePortalDetected = visible;
                         nai.everCaptivePortalDetected |= visible;
-                        if (nai.lastCaptivePortalDetected &&
-                            Settings.Global.CAPTIVE_PORTAL_MODE_AVOID == getCaptivePortalMode()) {
-                            if (DBG) log("Avoiding captive portal network: " + nai.name());
-                            nai.asyncChannel.sendMessage(
-                                    NetworkAgent.CMD_PREVENT_AUTOMATIC_RECONNECT);
-                            teardownUnneededNetwork(nai);
-                            break;
-                        }
                         updateCapabilities(oldScore, nai, nai.networkCapabilities);
                     }
                     if (!visible) {
@@ -2299,12 +2288,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
             return true;
         }
 
-        private int getCaptivePortalMode() {
-            return Settings.Global.getInt(mContext.getContentResolver(),
-                    Settings.Global.CAPTIVE_PORTAL_MODE,
-                    Settings.Global.CAPTIVE_PORTAL_MODE_PROMPT);
-        }
-
         private boolean maybeHandleNetworkAgentInfoMessage(Message msg) {
             switch (msg.what) {
                 default:
@@ -2614,28 +2597,14 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 "request NetworkCapabilities", ConnectivityManager.CALLBACK_CAP_CHANGED);
     }
 
-    private void handleTimedOutNetworkRequest(final NetworkRequestInfo nri) {
-        if (mNetworkRequests.get(nri.request) != null && mNetworkForRequestId.get(
-                nri.request.requestId) == null) {
-            handleRemoveNetworkRequest(nri, ConnectivityManager.CALLBACK_UNAVAIL);
-        }
-    }
-
     private void handleReleaseNetworkRequest(NetworkRequest request, int callingUid) {
         final NetworkRequestInfo nri = getNriForAppRequest(
                 request, callingUid, "release NetworkRequest");
-        if (nri != null) {
-            handleRemoveNetworkRequest(nri, ConnectivityManager.CALLBACK_RELEASED);
-        }
-    }
+        if (nri == null) return;
 
-    private void handleRemoveNetworkRequest(final NetworkRequestInfo nri, final int whichCallback) {
-        final String logCallbackType = ConnectivityManager.getCallbackName(whichCallback);
-        if (VDBG || (DBG && nri.request.isRequest())) {
-            log("releasing " + nri.request + " (" + logCallbackType + ")");
-        }
+        if (VDBG || (DBG && nri.request.isRequest())) log("releasing " + request);
         nri.unlinkDeathRecipient();
-        mNetworkRequests.remove(nri.request);
+        mNetworkRequests.remove(request);
         synchronized (mUidToNetworkRequestCount) {
             int requests = mUidToNetworkRequestCount.get(nri.mUid, 0);
             if (requests < 1) {
@@ -2729,7 +2698,7 @@ public class ConnectivityService extends IConnectivityManager.Stub
                 }
             }
         }
-        callCallbackForRequest(nri, null, whichCallback, 0);
+        callCallbackForRequest(nri, null, ConnectivityManager.CALLBACK_RELEASED, 0);
     }
 
     @Override
@@ -2966,11 +2935,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
                     handleRegisterNetworkRequestWithIntent(msg);
                     break;
                 }
-                case EVENT_TIMEOUT_NETWORK_REQUEST: {
-                    NetworkRequestInfo nri = (NetworkRequestInfo) msg.obj;
-                    handleTimedOutNetworkRequest(nri);
-                    break;
-                }
                 case EVENT_RELEASE_NETWORK_REQUEST_WITH_INTENT: {
                     handleReleaseNetworkRequestWithIntent((PendingIntent) msg.obj, msg.arg1);
                     break;
@@ -4615,28 +4579,9 @@ public class ConnectivityService extends IConnectivityManager.Stub
         } catch (Exception e) {
             loge("Exception in setDnsConfigurationForNetwork: " + e);
         }
-        final NetworkAgentInfo defaultNai = getDefaultNetwork();
-        if (defaultNai != null && defaultNai.network.netId == netId) {
-            setDefaultDnsSystemProperties(dnses);
-        }
         flushVmDnsCache();
     }
 
-    private void setDefaultDnsSystemProperties(Collection<InetAddress> dnses) {
-        int last = 0;
-        for (InetAddress dns : dnses) {
-            ++last;
-            String key = "net.dns" + last;
-            String value = dns.getHostAddress();
-            SystemProperties.set(key, value);
-        }
-        for (int i = last + 1; i <= mNumDnsEntries; ++i) {
-            String key = "net.dns" + i;
-            SystemProperties.set(key, "");
-        }
-        mNumDnsEntries = last;
-    }
-
     private String getNetworkPermission(NetworkCapabilities nc) {
         // TODO: make these permission strings AIDL constants instead.
         if (!nc.hasCapability(NET_CAPABILITY_NOT_RESTRICTED)) {
@@ -4853,7 +4798,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
         notifyLockdownVpn(newNetwork);
         handleApplyDefaultProxy(newNetwork.linkProperties.getHttpProxy());
         updateTcpBufferSizes(newNetwork);
-        setDefaultDnsSystemProperties(newNetwork.linkProperties.getDnsServers());
     }
 
     private void processListenRequests(NetworkAgentInfo nai, boolean capabilitiesChanged) {
@@ -5351,7 +5295,6 @@ public class ConnectivityService extends IConnectivityManager.Stub
     // notify only this one new request of the current state
     protected void notifyNetworkCallback(NetworkAgentInfo nai, NetworkRequestInfo nri) {
         int notifyType = ConnectivityManager.CALLBACK_AVAILABLE;
-        mHandler.removeMessages(EVENT_TIMEOUT_NETWORK_REQUEST, nri);
         if (nri.mPendingIntent == null) {
             callCallbackForRequest(nri, nai, notifyType, 0);
         } else {