diff --git a/protocols/ospf/protocol/src/test/java/org/onosproject/ospf/protocol/lsa/linksubtype/UnknownLinkSubTypeTest.java b/protocols/ospf/protocol/src/test/java/org/onosproject/ospf/protocol/lsa/linksubtype/UnknownLinkSubTypeTest.java
new file mode 100644
index 0000000..8f2b31b
--- /dev/null
+++ b/protocols/ospf/protocol/src/test/java/org/onosproject/ospf/protocol/lsa/linksubtype/UnknownLinkSubTypeTest.java
@@ -0,0 +1,110 @@
+/*
+ * Copyright 2016 Open Networking Laboratory
+ *
+ * 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.ospf.protocol.lsa.linksubtype;
+
+import org.jboss.netty.buffer.ChannelBuffer;
+import org.jboss.netty.buffer.ChannelBuffers;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+import org.onosproject.ospf.protocol.lsa.TlvHeader;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+
+/**
+ * Unit test class for UnknownLinkSubType.
+ */
+public class UnknownLinkSubTypeTest {
+    private final byte[] packet = {0, 114, 0, 4, 0, 0, 0, 1};
+    private UnknownLinkSubType unknownLinkSubType;
+    private TlvHeader header;
+    private ChannelBuffer channelBuffer;
+    private byte[] result;
+
+    @Before
+    public void setUp() throws Exception {
+        unknownLinkSubType = new UnknownLinkSubType(new TlvHeader());
+    }
+
+    @After
+    public void tearDown() throws Exception {
+        unknownLinkSubType = null;
+        header = null;
+    }
+
+    /**
+     * Tests value() getter method.
+     */
+    @Test
+    public void testValue() throws Exception {
+        unknownLinkSubType.setValue(packet);
+        assertThat(unknownLinkSubType.value(), is(notNullValue()));
+    }
+
+    /**
+     * Tests value() setter method.
+     */
+    @Test
+    public void testSetValue() throws Exception {
+        unknownLinkSubType.setValue(packet);
+        assertThat(unknownLinkSubType.value(), is(notNullValue()));
+    }
+
+    /**
+     * Tests readFrom() method.
+     */
+    @Test
+    public void testReadFrom() throws Exception {
+        header = new TlvHeader();
+        header.setTlvLength(8);
+        header.setTlvType(114);
+        unknownLinkSubType = new UnknownLinkSubType(header);
+        channelBuffer = ChannelBuffers.copiedBuffer(packet);
+        unknownLinkSubType.readFrom(channelBuffer);
+        assertThat(unknownLinkSubType, is(notNullValue()));
+    }
+
+    /**
+     * Tests asBytes() method.
+     */
+    @Test(expected = Exception.class)
+    public void testAsBytes() throws Exception {
+        result = unknownLinkSubType.asBytes();
+        assertThat(result, is(notNullValue()));
+    }
+
+
+    /**
+     * Tests getLinkSubTypeTlvBodyAsByteArray() method.
+     */
+    @Test
+    public void testGetLinkSubTypeTlvBodyAsByteArray() throws Exception {
+        channelBuffer = ChannelBuffers.copiedBuffer(packet);
+        unknownLinkSubType.readFrom(channelBuffer);
+        result = unknownLinkSubType.getLinkSubTypeTlvBodyAsByteArray();
+        assertThat(result, is(notNullValue()));
+    }
+
+    /**
+     * Tests to string method.
+     */
+    @Test
+    public void testToString() throws Exception {
+        assertThat(unknownLinkSubType.toString(), is(notNullValue()));
+    }
+}
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