diff --git a/utils/misc/src/test/java/org/onlab/util/HexStringTest.java b/utils/misc/src/test/java/org/onlab/util/HexStringTest.java
new file mode 100644
index 0000000..c20238f
--- /dev/null
+++ b/utils/misc/src/test/java/org/onlab/util/HexStringTest.java
@@ -0,0 +1,70 @@
+package org.onlab.util;
+
+import org.junit.Test;
+
+import com.esotericsoftware.minlog.Log;
+
+import junit.framework.TestCase;
+
+/**
+ * Test of the Hexstring.
+ *
+ */
+
+public class HexStringTest extends TestCase {
+
+    @Test
+    public void testMarshalling() throws Exception {
+        String dpidStr = "00:00:00:23:20:2d:16:71";
+        long dpid = HexString.toLong(dpidStr);
+        String testStr = HexString.toHexString(dpid);
+        TestCase.assertEquals(dpidStr, testStr);
+    }
+
+    @Test
+    public void testToLong() {
+        String dpidStr = "3e:1f:01:fc:72:8c:63:31";
+        long valid = 0x3e1f01fc728c6331L;
+        long testLong = HexString.toLong(dpidStr);
+        TestCase.assertEquals(valid, testLong);
+    }
+
+    @Test
+    public void testToLongMSB() {
+        String dpidStr = "ca:7c:5e:d1:64:7a:95:9b";
+        long valid = -3856102927509056101L;
+        long testLong = HexString.toLong(dpidStr);
+        TestCase.assertEquals(valid, testLong);
+    }
+
+    @Test
+    public void testToLongError() {
+        String dpidStr = "09:08:07:06:05:04:03:02:01";
+        try {
+            HexString.toLong(dpidStr);
+            fail("HexString.toLong() should have thrown a NumberFormatException");
+        } catch (NumberFormatException expected) {
+            Log.info("HexString.toLong() have thrown a NumberFormatException");
+        }
+    }
+
+    @Test
+    public void testToStringBytes() {
+        byte[] dpid = {0, 0, 0, 0, 0, 0, 0, -1 };
+        String valid = "00:00:00:00:00:00:00:ff";
+        String testString = HexString.toHexString(dpid);
+        TestCase.assertEquals(valid, testString);
+    }
+
+    @Test
+    public void testFromHexStringError() {
+        String invalidStr = "00:00:00:00:00:00:ffff";
+        try {
+            HexString.fromHexString(invalidStr);
+            fail("HexString.fromHexString() should have thrown a NumberFormatException");
+        } catch (NumberFormatException expected) {
+            Log.info("HexString.toLong() have thrown a NumberFormatException");
+        }
+    }
+}
+