diff --git a/utils/misc/src/main/java/org/onlab/packet/MacAddress.java b/utils/misc/src/main/java/org/onlab/packet/MacAddress.java
index 1027708..7908d71 100644
--- a/utils/misc/src/main/java/org/onlab/packet/MacAddress.java
+++ b/utils/misc/src/main/java/org/onlab/packet/MacAddress.java
@@ -18,12 +18,15 @@
 import com.google.common.collect.ImmutableSet;
 import java.util.Arrays;
 import java.util.Set;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
 
 /**
  * The class representing MAC address.
  */
 public class MacAddress {
 
+    private static final Pattern MAC_PATTERN = Pattern.compile("^([0-9A-Fa-f]{2}[:]){5}([0-9A-Fa-f]{2})$");
     /**
      * First MAC address in ONOS OUI range.
      */
@@ -77,13 +80,12 @@
      * @throws IllegalArgumentException if the string cannot be parsed as a MAC address.
      */
     public static MacAddress valueOf(final String address) {
-        final String[] elements = address.split(":");
-        if (elements.length != MacAddress.MAC_ADDRESS_LENGTH) {
+        if (!isValid(address)) {
             throw new IllegalArgumentException(
                     "Specified MAC Address must contain 12 hex digits"
                             + " separated pairwise by :'s.");
         }
-
+        final String[] elements = address.split(":");
         final byte[] addressInBytes = new byte[MacAddress.MAC_ADDRESS_LENGTH];
         for (int i = 0; i < MacAddress.MAC_ADDRESS_LENGTH; i++) {
             final String element = elements[i];
@@ -273,4 +275,9 @@
         }
         return builder.toString();
     }
+
+    private static boolean isValid(final String mac) {
+        Matcher matcher = MAC_PATTERN.matcher(mac);
+        return matcher.matches();
+    }
 }
diff --git a/utils/misc/src/test/java/org/onlab/packet/MacAddressTest.java b/utils/misc/src/test/java/org/onlab/packet/MacAddressTest.java
index 38a3b43..468107e 100644
--- a/utils/misc/src/test/java/org/onlab/packet/MacAddressTest.java
+++ b/utils/misc/src/test/java/org/onlab/packet/MacAddressTest.java
@@ -46,6 +46,10 @@
 
     private static final String INVALID_STR = "invalid";
     private static final byte[] INVALID_BYTE = {(byte) 0xaa};
+    private static final String INVALID_MAC_ADDITIONAL_COLON = "00:00:00:00:00:00:";
+    private static final String INVALID_MAC_OCTET_TOO_LONG = "000:000:000:000:000:00";
+    private static final String INVALID_MAC_OCTET_TOO_SHORT = "00:0:00:00:00:00";
+
 
     @Test
     public void testValueOfString() throws Exception {
@@ -57,6 +61,21 @@
         MacAddress.valueOf(INVALID_STR);
     }
 
+    @Test(expected = IllegalArgumentException.class)
+    public void testValueOfInvalidStringWithAdditionalColon() throws Exception {
+        MacAddress.valueOf(INVALID_MAC_ADDITIONAL_COLON);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testValueOfInvalidStringWithTooLongOctet() throws Exception {
+        MacAddress.valueOf(INVALID_MAC_OCTET_TOO_LONG);
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void testValueOfInvalidStringWithTooShortOctet() throws Exception {
+        MacAddress.valueOf(INVALID_MAC_OCTET_TOO_SHORT);
+    }
+
     @Test
     public void testValueOfByte() throws Exception {
         assertArrayEquals(MAC_ONOS_BYTE, MacAddress.valueOf(MAC_ONOS_BYTE).toBytes());