diff --git a/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java b/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
index 92f1953..b8689d6 100644
--- a/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
+++ b/service-t/src/com/android/server/ethernet/EthernetServiceImpl.java
@@ -108,11 +108,7 @@
             PermissionUtils.enforceRestrictedNetworkPermission(mContext, TAG);
         }
 
-        // This causes thread-unsafe access on mIpConfigurations which might
-        // race with calls to EthernetManager#updateConfiguration().
-        // EthernetManager#getConfiguration() has been marked as
-        // @UnsupportedAppUsage since Android R.
-        return mTracker.getIpConfiguration(iface);
+        return new IpConfiguration(mTracker.getIpConfiguration(iface));
     }
 
     /**
diff --git a/service-t/src/com/android/server/ethernet/EthernetTracker.java b/service-t/src/com/android/server/ethernet/EthernetTracker.java
index a60592f..71f289e 100644
--- a/service-t/src/com/android/server/ethernet/EthernetTracker.java
+++ b/service-t/src/com/android/server/ethernet/EthernetTracker.java
@@ -31,6 +31,8 @@
 import android.net.ITetheredInterfaceCallback;
 import android.net.InterfaceConfigurationParcel;
 import android.net.IpConfiguration;
+import android.net.IpConfiguration.IpAssignment;
+import android.net.IpConfiguration.ProxySettings;
 import android.net.LinkAddress;
 import android.net.NetworkCapabilities;
 import android.net.StaticIpConfiguration;
@@ -109,7 +111,6 @@
     /** Mapping between {iface name | mac address} -> {NetworkCapabilities} */
     private final ConcurrentHashMap<String, NetworkCapabilities> mNetworkCapabilities =
             new ConcurrentHashMap<>();
-    /** Mapping between {iface name | mac address} -> {IpConfiguration} */
     private final ConcurrentHashMap<String, IpConfiguration> mIpConfigurations =
             new ConcurrentHashMap<>();
 
@@ -297,7 +298,7 @@
     }
 
     private IpConfiguration getIpConfigurationForCallback(String iface, int state) {
-        return (state == EthernetManager.STATE_ABSENT) ? null : getIpConfiguration(iface);
+        return (state == EthernetManager.STATE_ABSENT) ? null : getOrCreateIpConfiguration(iface);
     }
 
     private void ensureRunningOnEthernetServiceThread() {
@@ -390,83 +391,8 @@
         mHandler.post(() -> setInterfaceAdministrativeState(iface, enabled, cb));
     }
 
-    private @Nullable String getHwAddress(String iface) {
-        if (getInterfaceRole(iface) == EthernetManager.ROLE_SERVER) {
-            return mTetheringInterfaceHwAddr;
-        }
-
-        return mFactory.getHwAddress(iface);
-    }
-
-    /**
-     * Get the IP configuration of the interface, or the default if the interface doesn't exist.
-     * @param iface the name of the interface to retrieve.
-     *
-     * @return The IP configuration
-     */
-    public IpConfiguration getIpConfiguration(String iface) {
-        return getIpConfiguration(iface, getHwAddress(iface));
-    }
-
-    private IpConfiguration getIpConfiguration(String iface, @Nullable String hwAddress) {
-        // Look up Ip configuration first by ifname, then by MAC address.
-        IpConfiguration ipConfig = mIpConfigurations.get(iface);
-        if (ipConfig != null) {
-            return ipConfig;
-        }
-
-        if (hwAddress == null) {
-            // should never happen.
-            Log.wtf(TAG, "No hardware address for interface " + iface);
-        } else {
-            ipConfig = mIpConfigurations.get(hwAddress);
-        }
-
-        if (ipConfig == null) {
-            ipConfig = new IpConfiguration.Builder().build();
-        }
-
-        return ipConfig;
-    }
-
-    private NetworkCapabilities getNetworkCapabilities(String iface) {
-        return getNetworkCapabilities(iface, getHwAddress(iface));
-    }
-
-    private NetworkCapabilities getNetworkCapabilities(String iface, @Nullable String hwAddress) {
-        // Look up network capabilities first by ifname, then by MAC address.
-        NetworkCapabilities networkCapabilities = mNetworkCapabilities.get(iface);
-        if (networkCapabilities != null) {
-            return networkCapabilities;
-        }
-
-        if (hwAddress == null) {
-            // should never happen.
-            Log.wtf(TAG, "No hardware address for interface " + iface);
-        } else {
-            networkCapabilities = mNetworkCapabilities.get(hwAddress);
-        }
-
-        if (networkCapabilities != null) {
-            return networkCapabilities;
-        }
-
-        final NetworkCapabilities.Builder builder = createNetworkCapabilities(
-                false /* clear default capabilities */, null, null)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_CONGESTED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED)
-                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VCN_MANAGED);
-
-        if (isValidTestInterface(iface)) {
-            builder.addTransportType(NetworkCapabilities.TRANSPORT_TEST);
-        } else {
-            builder.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
-        }
-
-        return builder.build();
+    IpConfiguration getIpConfiguration(String iface) {
+        return mIpConfigurations.get(iface);
     }
 
     @VisibleForTesting(visibility = PACKAGE)
@@ -507,8 +433,8 @@
      * NET_CAPABILITY_NOT_RESTRICTED) capability. Otherwise, returns false.
      */
     boolean isRestrictedInterface(String iface) {
-        final NetworkCapabilities nc = getNetworkCapabilities(iface);
-        return !nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED);
+        final NetworkCapabilities nc = mNetworkCapabilities.get(iface);
+        return nc != null && !nc.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED);
     }
 
     void addListener(IEthernetServiceListener listener, boolean canUseRestrictedNetworks) {
@@ -697,9 +623,17 @@
             return;
         }
 
-        final NetworkCapabilities nc = getNetworkCapabilities(iface, hwAddress);
-        final IpConfiguration ipConfiguration = getIpConfiguration(iface, hwAddress);
+        NetworkCapabilities nc = mNetworkCapabilities.get(iface);
+        if (nc == null) {
+            // Try to resolve using mac address
+            nc = mNetworkCapabilities.get(hwAddress);
+            if (nc == null) {
+                final boolean isTestIface = iface.matches(TEST_IFACE_REGEXP);
+                nc = createDefaultNetworkCapabilities(isTestIface);
+            }
+        }
 
+        IpConfiguration ipConfiguration = getOrCreateIpConfiguration(iface);
         Log.d(TAG, "Tracking interface in client mode: " + iface);
         mFactory.addInterface(iface, hwAddress, ipConfiguration, nc);
 
@@ -839,6 +773,25 @@
         return new EthernetTrackerConfig(configString.split(";", /* limit of tokens */ 4));
     }
 
+    private static NetworkCapabilities createDefaultNetworkCapabilities(boolean isTestIface) {
+        NetworkCapabilities.Builder builder = createNetworkCapabilities(
+                false /* clear default capabilities */, null, null)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_RESTRICTED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_METERED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_ROAMING)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_CONGESTED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_SUSPENDED)
+                .addCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VCN_MANAGED);
+
+        if (isTestIface) {
+            builder.addTransportType(NetworkCapabilities.TRANSPORT_TEST);
+        } else {
+            builder.addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET);
+        }
+
+        return builder.build();
+    }
+
     /**
      * Parses a static list of network capabilities
      *
@@ -973,6 +926,15 @@
         return new IpConfiguration.Builder().setStaticIpConfiguration(staticIpConfig).build();
     }
 
+    private IpConfiguration getOrCreateIpConfiguration(String iface) {
+        IpConfiguration ret = mIpConfigurations.get(iface);
+        if (ret != null) return ret;
+        ret = new IpConfiguration();
+        ret.setIpAssignment(IpAssignment.DHCP);
+        ret.setProxySettings(ProxySettings.NONE);
+        return ret;
+    }
+
     private boolean isValidEthernetInterface(String iface) {
         return iface.matches(mIfaceMatch) || isValidTestInterface(iface);
     }
@@ -1059,7 +1021,7 @@
             pw.println("IP Configurations:");
             pw.increaseIndent();
             for (String iface : mIpConfigurations.keySet()) {
-                pw.println(iface + ": " + getIpConfiguration(iface));
+                pw.println(iface + ": " + mIpConfigurations.get(iface));
             }
             pw.decreaseIndent();
             pw.println();
@@ -1067,7 +1029,7 @@
             pw.println("Network Capabilities:");
             pw.increaseIndent();
             for (String iface : mNetworkCapabilities.keySet()) {
-                pw.println(iface + ": " + getNetworkCapabilities(iface));
+                pw.println(iface + ": " + mNetworkCapabilities.get(iface));
             }
             pw.decreaseIndent();
             pw.println();