diff --git a/api/src/com/cloud/api/commands/CreateNetworkOfferingCmd.java b/api/src/com/cloud/api/commands/CreateNetworkOfferingCmd.java
index bd3db8d2905..b444786ef1a 100644
--- a/api/src/com/cloud/api/commands/CreateNetworkOfferingCmd.java
+++ b/api/src/com/cloud/api/commands/CreateNetworkOfferingCmd.java
@@ -71,7 +71,7 @@ public class CreateNetworkOfferingCmd extends BaseCmd {
     @Parameter(name=ApiConstants.NETWORKRATE, type=CommandType.INTEGER, description="data transfer rate in megabits per second allowed")
     private Integer networkRate;
     
-    @Parameter(name=ApiConstants.CONSERVE_MODE, type=CommandType.BOOLEAN, required = true, description="true if the network offering is IP conserve mode enabled")
+    @Parameter(name=ApiConstants.CONSERVE_MODE, type=CommandType.BOOLEAN, description="true if the network offering is IP conserve mode enabled")
     private Boolean conserveMode;
     
     @IdentityMapper(entityTableName="disk_offering")
@@ -139,6 +139,9 @@ public class CreateNetworkOfferingCmd extends BaseCmd {
     }
 
     public Boolean getConserveMode() {
+        if (conserveMode == null) {
+            return true;
+        }
         return conserveMode;
     }
 
diff --git a/server/src/com/cloud/network/NetworkManagerImpl.java b/server/src/com/cloud/network/NetworkManagerImpl.java
index 3d13bf3bcf1..b4a444ca4b5 100755
--- a/server/src/com/cloud/network/NetworkManagerImpl.java
+++ b/server/src/com/cloud/network/NetworkManagerImpl.java
@@ -743,12 +743,16 @@ public class NetworkManagerImpl implements NetworkManager, NetworkService, Manag
             Set<Service> services = ipToServices.get(ip);
             Provider provider = null;
             for (Service service : services) {
-                Provider curProvider = (Provider)serviceToProviders.get(service).toArray()[0];
-                //We don't support multiply providers for one service now
+                Set<Provider> curProviders = serviceToProviders.get(service);
+                if (curProviders == null || curProviders.isEmpty()) {
+                    continue;
+                }
+                Provider curProvider = (Provider)curProviders.toArray()[0];
                 if (provider == null) {
                     provider = curProvider;
                     continue;
                 }
+                //We don't support multiply providers for one service now
                 if (!provider.equals(curProvider)) {
                     throw new CloudRuntimeException("There would be multiply providers for IP " + ip.getAddress() + " with the new network offering!");
                 }
@@ -767,8 +771,14 @@ public class NetworkManagerImpl implements NetworkManager, NetworkService, Manag
             return true;
         }
         //We only support one provider for one service now
-        Provider oldProvider = (Provider)serviceToProviders.get((Service)services.toArray()[0]).toArray()[0];
-        Provider newProvider = (Provider)serviceToProviders.get(service).toArray()[0];
+        Set<Provider> oldProviders = serviceToProviders.get((Service)services.toArray()[0]);
+        Provider oldProvider = (Provider)oldProviders.toArray()[0];
+        //Since IP already has service to bind with, the oldProvider can't be null
+        Set<Provider> newProviders = serviceToProviders.get(service);
+        if (newProviders == null || newProviders.isEmpty()) {
+            throw new CloudRuntimeException("There is no new provider for IP " + publicIp.getAddress() + " of service " + service.getName() + "!");
+        }
+        Provider newProvider = (Provider)newProviders.toArray()[0];
         if (!oldProvider.equals(newProvider)) {
             throw new CloudRuntimeException("There would be multiply providers for IP " + publicIp.getAddress() + "!");
         }
diff --git a/setup/db/create-schema.sql b/setup/db/create-schema.sql
index a0875b7f5a6..61f191132c6 100755
--- a/setup/db/create-schema.sql
+++ b/setup/db/create-schema.sql
@@ -259,7 +259,7 @@ CREATE TABLE `cloud`.`network_offerings` (
   `system_only` int(1) unsigned NOT NULL DEFAULT 0 COMMENT 'Is this network offering for system use only',
   `specify_vlan` int(1) unsigned NOT NULL DEFAULT 0 COMMENT 'Should the user specify vlan',
   `service_offering_id` bigint unsigned COMMENT 'service offering id that virtual router is tied to',
-  `conserve_mode` int(1) unsigned NOT NULL DEFAULT 0 COMMENT 'Is this network offering is IP conserve mode enabled',
+  `conserve_mode` int(1) unsigned NOT NULL DEFAULT 1 COMMENT 'Is this network offering is IP conserve mode enabled',
   `created` datetime NOT NULL COMMENT 'time the entry was created',
   `removed` datetime DEFAULT NULL COMMENT 'time the entry was removed',
   `default` int(1) unsigned NOT NULL DEFAULT 0 COMMENT '1 if network offering is default',