diff --git a/server/src/com/cloud/network/NetworkServiceImpl.java b/server/src/com/cloud/network/NetworkServiceImpl.java
index 20319ffe7d4..df44ce0ea27 100755
--- a/server/src/com/cloud/network/NetworkServiceImpl.java
+++ b/server/src/com/cloud/network/NetworkServiceImpl.java
@@ -806,7 +806,7 @@ public class NetworkServiceImpl implements  NetworkService, Manager {
         	int cidrSize = NetUtils.getIp6CidrSize(ip6Cidr);
         	// Ipv6 cidr limit should be at least /64
         	if (cidrSize < 64) {
-        		throw new InvalidParameterValueException("The cidr size of IPv6 must be bigger than 64 bits!");
+        		throw new InvalidParameterValueException("The cidr size of IPv6 network must be no less than 64 bits!");
         	}
         }
 
diff --git a/utils/src/com/cloud/utils/net/NetUtils.java b/utils/src/com/cloud/utils/net/NetUtils.java
index 8bfd3769029..b81aff681d8 100755
--- a/utils/src/com/cloud/utils/net/NetUtils.java
+++ b/utils/src/com/cloud/utils/net/NetUtils.java
@@ -1178,12 +1178,15 @@ public class NetUtils {
 	public static String getIp6FromRange(String ip6Range) {
     	String[] ips = ip6Range.split("-");
     	String startIp = ips[0];
-    	long gap = countIp6InRange(ip6Range);
     	IPv6Address start = IPv6Address.fromString(startIp);
     	// Find a random number based on lower 32 bits
-    	int d = _rand.nextInt((int)(gap % Integer.MAX_VALUE));
+    	long gap = countIp6InRange(ip6Range);
+    	if (gap > Integer.MAX_VALUE) {
+    		gap = Integer.MAX_VALUE;
+    	}
+    	int next = _rand.nextInt((int)(gap));
     	// And a number based on the difference of lower 32 bits
-    	IPv6Address ip = start.add(d);
+    	IPv6Address ip = start.add(next);
     	return ip.toString();
 	}
 
diff --git a/utils/test/com/cloud/utils/net/NetUtilsTest.java b/utils/test/com/cloud/utils/net/NetUtilsTest.java
index 6290cd6390d..9beb6ca8bf1 100644
--- a/utils/test/com/cloud/utils/net/NetUtilsTest.java
+++ b/utils/test/com/cloud/utils/net/NetUtilsTest.java
@@ -16,16 +16,20 @@
 // under the License.
 package com.cloud.utils.net;
 
-import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeSet;
 
 import junit.framework.TestCase;
 
+import org.apache.log4j.Logger;
 import org.junit.Test;
 
+import com.googlecode.ipv6.IPv6Address;
+
 public class NetUtilsTest extends TestCase {
 
+    private static final Logger s_logger = Logger.getLogger(NetUtilsTest.class);
+    
     @Test
     public void testGetRandomIpFromCidr() {
         String cidr = "192.168.124.1";
@@ -82,5 +86,15 @@ public class NetUtilsTest extends TestCase {
     	assertEquals(NetUtils.countIp6InRange("1234:5678::1-1234:5678::2"), 2);
     	assertEquals(NetUtils.countIp6InRange("1234:5678::2-1234:5678::0"), 0);
     	assertEquals(NetUtils.getIp6FromRange("1234:5678::1-1234:5678::1"), "1234:5678::1");
+    	String ipString = null;
+    	IPv6Address ipStart = IPv6Address.fromString("1234:5678::1");
+    	IPv6Address ipEnd = IPv6Address.fromString("1234:5678::8000:0000");
+    	for (int i = 0; i < 10; i ++) {
+    		ipString = NetUtils.getIp6FromRange(ipStart.toString() + "-" + ipEnd.toString());
+    		s_logger.info("IP is " + ipString);
+    		IPv6Address ip = IPv6Address.fromString(ipString);
+    		assertTrue(ip.compareTo(ipStart) >= 0);
+    		assertTrue(ip.compareTo(ipEnd) <= 0);
+    	}
     }
 }