Fix IP address conflict

Author: Pearl Dsilva

server/src/main/java/com/cloud/network/IpAddressManagerImpl.java

@@ -32,6 +32,7 @@
 
 import org.apache.cloudstack.acl.ControlledEntity.ACLType;
 import org.apache.cloudstack.acl.SecurityChecker.AccessType;
+import org.apache.cloudstack.api.ApiConstants;
 import org.apache.cloudstack.api.response.AcquirePodIpCmdResponse;
 import org.apache.cloudstack.context.CallContext;
 import org.apache.cloudstack.engine.orchestration.service.NetworkOrchestrationService;
@@ -850,10 +851,16 @@ public IPAddressVO doInTransaction(TransactionStatus status) throws Insufficient
                     errorMessage.append(", network id=" + guestNetworkId);
                 }
                 sc.setJoinParameters("vlan", "type", vlanUse);
-
+                String routerIpAddress = null;
+                if (network != null) {
+                    NetworkDetailVO routerIpDetail = _networkDetailsDao.findDetail(network.getId(), ApiConstants.ROUTER_IP);
+                    routerIpAddress = routerIpDetail != null ? routerIpDetail.getValue() : null;
+                }
                 if (requestedIp != null) {
                     sc.addAnd("address", SearchCriteria.Op.EQ, requestedIp);
                     errorMessage.append(": requested ip " + requestedIp + " is not available");
+                } else if (routerIpAddress != null) {
+                    sc.addAnd("address", Op.NEQ, routerIpAddress);
                 }
 
                 boolean ascOrder = ! forSystemVms;
@@ -2104,7 +2111,6 @@ public void allocateDirectIp(final NicProfile nic, final DataCenter dc, final Vi
             public void doInTransactionWithoutResult(TransactionStatus status) throws InsufficientAddressCapacityException {
                 //This method allocates direct ip for the Shared network in Advance zones
                 boolean ipv4 = false;
-
                 if (network.getGateway() != null) {
                     if (nic.getIPv4Address() == null) {
                         PublicIp ip = null;