Thanks Collin for the reply. I do not have network congestion. I merely wish to increase my processing window and let the users access the production environment until ETL is done. Once ETL is done, I wish to make the instance that ETL has worked on to be the production environment that users will be pointing through a swap of server addresses, without users impacted and downtime.

Hmmm, the only way I can think off that might come close is to use EEM with HSRP and schedule a change, however there will be a moment of downtime. You could also try GSS with an ACE, but that's a lot of money. I don't know much about ETL, but could you create a separate layer 2 network just for ETL and the servers? Users will always point to "prod" IP's and the ETL would use the isolated network on the backend.