diff --git a/api/src/com/cloud/api/commands/CreateNetworkCmd.java b/api/src/com/cloud/api/commands/CreateNetworkCmd.java
index fcc1fa7ab31..336dcec53b1 100644
--- a/api/src/com/cloud/api/commands/CreateNetworkCmd.java
+++ b/api/src/com/cloud/api/commands/CreateNetworkCmd.java
@@ -262,6 +262,10 @@ public class CreateNetworkCmd extends BaseCmd {
     @Override
 	// an exception thrown by createNetwork() will be caught by the dispatcher. 
     public void execute() throws InsufficientCapacityException, ConcurrentOperationException, ResourceAllocationException{
+        if (getStartIpv6() != null && getStartIp() != null) {
+        	throw new InvalidParameterValueException("Cannot support dualstack at this moment!");
+        }
+        
         Network result = _networkService.createGuestNetwork(this);
         if (result != null) {
             NetworkResponse response = _responseGenerator.createNetworkResponse(result);
diff --git a/server/src/com/cloud/network/NetworkServiceImpl.java b/server/src/com/cloud/network/NetworkServiceImpl.java
index 42a05a62dae..1e3c9ebf9b7 100755
--- a/server/src/com/cloud/network/NetworkServiceImpl.java
+++ b/server/src/com/cloud/network/NetworkServiceImpl.java
@@ -764,10 +764,6 @@ public class NetworkServiceImpl implements  NetworkService, Manager {
 
         UserContext.current().setAccountId(owner.getAccountId());
 
-        if (startIPv6 != null && startIP != null) {
-        	throw new InvalidParameterValueException("Cannot support dualstack at this moment!");
-        }
-        
         boolean ipv4 = false, ipv6 = false;
         if (startIP != null) {
         	ipv4 = true;