Configure and prepare your clients such that
        the transition of HTTP clients from the old deployment to the new deployment is smooth and
        happens by switching the Domain Name System (DNS) entry.
               
                  
                  These changes can be done gradually over time because after these changes
                are completed everything continues to work as before the changes. This includes some
                changes to the source environment.
                  
                  To prepare clients:
                  
                
               
               
                  - Get a DNS name issued from DNS issuing authority. Point this DNS name to the
                    source environment load balancer.
                        
                        If you are already using a DNS name in clients, skip this
                        step. 
 
- Create a new port in the source environment load balancer that matches the
                    target port number. Add routing rule to this new port to route to the original
                    load balancer port in the source environment.
- Change all clients to use the DNS name and new port.
                        
                        For SSL, it might be required that the trust certificate for the
                        target environment server has to be pre-configured at the client so that
                        transition from the source to the target environment works smoothly. 
 
- If you were already set up to use a global DNS name, ensure that the Oracle
                    WebLogic Server front end host points to the load balancer and not the DNS name. 
                        
                        Ensure that the loopback HTTP invokes point to the Oracle
                        WebLogic Server front end host/port. For SOA, also ensure that the loopback
                        abstract WSDL/Schema references point to the WebLogic FE host/port. These changes ensure that: 
                           - 
                              
                              Callbacks come back to the source domain that issued the
                                request, after transitioning to the target. 
- 
                              
                              Loopbacks in the source domain come back to the source
                                domain after transitioning to the target.