Testing subnet

I’ve read a bit in the documentation about test networking, but I wanted to ask the community what they have configured for themselves when it comes to a test network.

We’re an infoblox shop, with two DCs testing failover in our VCenters that do not utilize nsx or any kind of spread network.  So if systems are moved to the secondary DC, they will get a new IP in a completely different subnet.

It would be difficult to fail over a tiered application and have to register hostnames in our IB system if the secondary IP subnet can still communicate across the network and interfere with production systems.  Networking asked for requirements and I plan on doing my own testing on this.

I’m just wondering what everyone else had up and running and if they had any tips.