diff --git a/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java b/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
index bb7a47a..6c72a06 100644
--- a/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
+++ b/app/src/main/java/org/onosproject/segmentrouting/SegmentRoutingManager.java
@@ -201,7 +201,7 @@
     private ComponentConfigService compCfgService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY)
-    private NeighbourResolutionService neighbourResolutionService;
+    public NeighbourResolutionService neighbourResolutionService;
 
     @Reference(cardinality = ReferenceCardinality.MANDATORY)
     public CoreService coreService;
diff --git a/app/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java b/app/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java
index e4b9949..93e76ad 100644
--- a/app/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java
+++ b/app/src/main/java/org/onosproject/segmentrouting/config/DeviceConfiguration.java
@@ -46,6 +46,7 @@
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Objects;
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.stream.Collectors;
@@ -468,7 +469,27 @@
     }
 
     /**
-     * Returns the configured subnet prefixes for a segment router.
+     * Returns configured subnets for a segment router.
+     *
+     * @param deviceId device identifier
+     * @return list of ip prefixes or null if not found
+     */
+    public Set<IpPrefix> getConfiguredSubnets(DeviceId deviceId) {
+        Set<IpPrefix> subnets = srManager.interfaceService.getInterfaces().stream()
+                .filter(intf -> Objects.equals(deviceId, intf.connectPoint().deviceId()))
+                .flatMap(intf -> intf.ipAddressesList().stream())
+                .map(InterfaceIpAddress::subnetAddress)
+                .collect(Collectors.toSet());
+
+        if (subnets.isEmpty()) {
+            log.debug(NO_SUBNET, deviceId);
+            return Collections.emptySet();
+        }
+        return subnets;
+    }
+
+    /**
+     * Returns all subnets for a segment router, including subnets learnt from route service.
      *
      * @param deviceId device identifier
      * @return list of ip prefixes or null if not found
@@ -501,17 +522,15 @@
             return Collections.emptySet();
         }
 
-        Set<IpPrefix> subnets =
-                srManager.interfaceService.getInterfacesByPort(connectPoint).stream()
-                        .flatMap(intf -> intf.ipAddressesList().stream())
-                        .map(InterfaceIpAddress::subnetAddress)
-                        .collect(Collectors.toSet());
+        Set<IpPrefix> subnets = srManager.interfaceService.getInterfacesByPort(connectPoint).stream()
+                .flatMap(intf -> intf.ipAddressesList().stream())
+                .map(InterfaceIpAddress::subnetAddress)
+                .collect(Collectors.toSet());
 
         if (subnets.isEmpty()) {
             log.debug(NO_SUBNET, connectPoint);
             return Collections.emptySet();
         }
-
         return subnets;
     }
 
@@ -610,8 +629,7 @@
      * within any subnet defined in the router
      */
     public boolean inSameSubnet(DeviceId deviceId, IpAddress hostIp) {
-
-        Set<IpPrefix> subnets = getSubnets(deviceId);
+        Set<IpPrefix> subnets = getConfiguredSubnets(deviceId);
         if (subnets == null) {
             return false;
         }
@@ -622,7 +640,6 @@
                 return true;
             }
         }
-
         return false;
     }
 
diff --git a/app/src/test/java/org/onosproject/segmentrouting/config/DeviceConfigurationTest.java b/app/src/test/java/org/onosproject/segmentrouting/config/DeviceConfigurationTest.java
new file mode 100644
index 0000000..469def0
--- /dev/null
+++ b/app/src/test/java/org/onosproject/segmentrouting/config/DeviceConfigurationTest.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright 2019-present Open Networking Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.segmentrouting.config;
+
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.google.common.collect.Lists;
+import com.google.common.collect.Sets;
+import org.junit.Before;
+import org.junit.Test;
+import org.onlab.packet.IpPrefix;
+import org.onlab.packet.MacAddress;
+import org.onlab.packet.VlanId;
+import org.onosproject.net.ConnectPoint;
+import org.onosproject.net.DeviceId;
+import org.onosproject.net.PortNumber;
+import org.onosproject.net.config.NetworkConfigRegistry;
+import org.onosproject.net.config.basics.InterfaceConfig;
+import org.onosproject.net.host.InterfaceIpAddress;
+import org.onosproject.net.intf.Interface;
+import org.onosproject.net.intf.InterfaceService;
+import org.onosproject.net.neighbour.NeighbourResolutionService;
+import org.onosproject.segmentrouting.SegmentRoutingManager;
+
+import java.io.InputStream;
+import java.util.List;
+import java.util.Set;
+
+import static org.easymock.EasyMock.anyObject;
+import static org.easymock.EasyMock.createMock;
+import static org.easymock.EasyMock.eq;
+import static org.easymock.EasyMock.expect;
+import static org.easymock.EasyMock.expectLastCall;
+import static org.easymock.EasyMock.replay;
+import static org.junit.Assert.*;
+
+public class DeviceConfigurationTest {
+    private static final DeviceId DEV1 = DeviceId.deviceId("of:1");
+    private static final String CONFIG_KEY = "segmentrouting";
+    private static final PortNumber PORT1 = PortNumber.portNumber(1);
+    private static final PortNumber PORT2 = PortNumber.portNumber(2);
+    private static final ConnectPoint CP1 = new ConnectPoint(DEV1, PORT1);
+    private static final ConnectPoint CP2 = new ConnectPoint(DEV1, PORT2);
+    private static final MacAddress MAC1 = MacAddress.valueOf("00:11:22:33:44:55");
+    private static final VlanId VLAN1 = VlanId.vlanId((short) 10);
+    private static final VlanId VLAN2 = VlanId.vlanId((short) 20);
+    private static final IpPrefix PREFIX1 = IpPrefix.valueOf("10.0.1.254/24");
+    private static final IpPrefix PREFIX2 = IpPrefix.valueOf("10.0.2.254/24");
+    private static final IpPrefix ROUTE1 = IpPrefix.valueOf("20.0.1.254/24");
+    private static final InterfaceIpAddress INTF1_IP = new InterfaceIpAddress(PREFIX1.address(), PREFIX1);
+    private static final InterfaceIpAddress INTF2_IP = new InterfaceIpAddress(PREFIX2.address(), PREFIX2);
+    private static final List<InterfaceIpAddress> IP_LIST1 = Lists.newArrayList(INTF1_IP);
+    private static final List<InterfaceIpAddress> IP_LIST2 = Lists.newArrayList(INTF2_IP);
+    private static final Interface INTF1 = new Interface("mock-intf1", CP1, IP_LIST1, MAC1,
+            null, VLAN1, null, null);
+    private static final Interface INTF2 = new Interface("mock-intf2", CP2, IP_LIST2, MAC1,
+            null, VLAN2, null, null);
+    private static final Set<Interface> INTERFACES = Sets.newHashSet(INTF1, INTF2);
+
+    private DeviceConfiguration devConfig;
+
+    @Before
+    public void setUp() throws Exception {
+        InterfaceService interfaceService;
+        NetworkConfigRegistry networkConfigService;
+        NeighbourResolutionService neighbourResolutionService;
+        SegmentRoutingManager srManager;
+
+        // Mock device netcfg
+        InputStream jsonStream = SegmentRoutingDeviceConfigTest.class.getResourceAsStream("/device.json");
+        ObjectMapper mapper = new ObjectMapper();
+        JsonNode jsonNode = mapper.readTree(jsonStream);
+        SegmentRoutingDeviceConfig srDevConfig = new SegmentRoutingDeviceConfig();
+        srDevConfig.init(DEV1, CONFIG_KEY, jsonNode, mapper, config -> { });
+
+        // Mock interface netcfg
+        jsonStream = InterfaceConfig.class.getResourceAsStream("/interface1.json");
+        jsonNode = mapper.readTree(jsonStream);
+        InterfaceConfig interfaceConfig1 = new InterfaceConfig();
+        interfaceConfig1.init(CP1, CONFIG_KEY, jsonNode, mapper, config -> { });
+        jsonStream = InterfaceConfig.class.getResourceAsStream("/interface2.json");
+        jsonNode = mapper.readTree(jsonStream);
+        InterfaceConfig interfaceConfig2 = new InterfaceConfig();
+        interfaceConfig2.init(CP1, CONFIG_KEY, jsonNode, mapper, config -> { });
+
+        networkConfigService = createMock(NetworkConfigRegistry.class);
+        expect(networkConfigService.getSubjects(DeviceId.class, SegmentRoutingDeviceConfig.class))
+                .andReturn(Sets.newHashSet(DEV1)).anyTimes();
+        expect(networkConfigService.getConfig(DEV1, SegmentRoutingDeviceConfig.class))
+                .andReturn(srDevConfig).anyTimes();
+        expect(networkConfigService.getSubjects(ConnectPoint.class, InterfaceConfig.class))
+                .andReturn(Sets.newHashSet(CP1, CP2)).anyTimes();
+        expect(networkConfigService.getConfig(CP1, InterfaceConfig.class)).andReturn(interfaceConfig1).anyTimes();
+        expect(networkConfigService.getConfig(CP2, InterfaceConfig.class)).andReturn(interfaceConfig2).anyTimes();
+        expect(networkConfigService.applyConfig(eq(CP1), eq(InterfaceConfig.class), anyObject()))
+                .andReturn(interfaceConfig1).anyTimes();
+        expect(networkConfigService.applyConfig(eq(CP2), eq(InterfaceConfig.class), anyObject()))
+                .andReturn(interfaceConfig2).anyTimes();
+        expect(networkConfigService.getConfig(null, SegmentRoutingAppConfig.class)).andReturn(null).anyTimes();
+        replay(networkConfigService);
+
+        interfaceService = createMock(InterfaceService.class);
+        expect(interfaceService.getInterfaces()).andReturn(INTERFACES).anyTimes();
+        expect(interfaceService.getInterfacesByPort(CP1)).andReturn(Sets.newHashSet(INTF1)).anyTimes();
+        expect(interfaceService.getInterfacesByPort(CP2)).andReturn(Sets.newHashSet(INTF2)).anyTimes();
+        replay(interfaceService);
+
+        neighbourResolutionService = createMock(NeighbourResolutionService.class);
+        neighbourResolutionService.registerNeighbourHandler(anyObject(ConnectPoint.class), anyObject(), anyObject());
+        expectLastCall().anyTimes();
+        replay(neighbourResolutionService);
+
+        srManager = new SegmentRoutingManager();
+        srManager.interfaceService = interfaceService;
+        srManager.cfgService = networkConfigService;
+        srManager.neighbourResolutionService = neighbourResolutionService;
+
+        devConfig = new DeviceConfiguration(srManager);
+        devConfig.addSubnet(CP2, ROUTE1);
+    }
+
+    @Test
+    public void getConfiguredSubnets() {
+        Set<IpPrefix> expect = Sets.newHashSet(PREFIX1, PREFIX2);
+        assertEquals(expect, devConfig.getConfiguredSubnets(DEV1));
+    }
+
+    @Test
+    public void getSubnets() {
+        Set<IpPrefix> expect = Sets.newHashSet(PREFIX1, PREFIX2, ROUTE1);
+        assertEquals(expect, devConfig.getSubnets(DEV1));
+    }
+
+    @Test
+    public void getPortSubnets() {
+        assertEquals(Sets.newHashSet(PREFIX1), devConfig.getPortSubnets(DEV1, PORT1));
+        assertEquals(Sets.newHashSet(PREFIX2), devConfig.getPortSubnets(DEV1, PORT2));
+    }
+
+    @Test
+    public void inSameSubnet() {
+        assertTrue(devConfig.inSameSubnet(DEV1, PREFIX1.address()));
+        assertTrue(devConfig.inSameSubnet(DEV1, PREFIX2.address()));
+        assertFalse(devConfig.inSameSubnet(DEV1, ROUTE1.address()));
+    }
+}
\ No newline at end of file
diff --git a/app/src/test/resources/interface1.json b/app/src/test/resources/interface1.json
new file mode 100644
index 0000000..0f7123f
--- /dev/null
+++ b/app/src/test/resources/interface1.json
@@ -0,0 +1,6 @@
+[
+  {
+    "ips" : [ "10.0.1.254/24" ],
+    "vlan-untagged": 10
+  }
+]
\ No newline at end of file
diff --git a/app/src/test/resources/interface2.json b/app/src/test/resources/interface2.json
new file mode 100644
index 0000000..114fbf5
--- /dev/null
+++ b/app/src/test/resources/interface2.json
@@ -0,0 +1,6 @@
+[
+  {
+    "ips" : [ "10.0.2.254/24" ],
+    "vlan-untagged": 20
+  }
+]
\ No newline at end of file