About Purpose
When the corresponding network objects are involved in recovery tasks such as migrate, recover, or resync, then set the purpose as Production on those network objects. Similarly, when the corresponding network objects are involved only in Rehearsal operations, then set the purpose as Rehearsal on those network objects.
To perform recovery operations such as migrate, recover, or resync, you need to pair the network objects with a purpose as Production from source data center with network objects with a purpose as Production in the target data center. IPv4 network objects (for example, subnets) can be paired with only IPv4 network objects, and IPv6 network objects can be paired with only IPv6 network objects.
When you want to perform the rehearsal operations, you can map the network objects with purpose as Production with network objects (corresponding to rehearsal networks) with purpose as Rehearsal in the target data center. For example, you can map the AWS Cloud Subnet (Production as purpose) to AWS Cloud Subnet (Rehearsal as purpose). Following figure explains the mapping across the data center:
See Mapping network objects (Production and Rehearsal mapping).
The create network pair operation eliminates the need to manually connect each virtual machine to a network at the recovery data center.
After you have paired the networks successfully, the target networks and the IP addresses are computed programmatically, and applied to the virtual machines. When you clone your virtual machines, ensure that you assign the appropriate host name and IP address to the cloned virtual machines.
For example:
In your source data center you have two subnets with Production and rehearsal as the purpose. The Production subnet is mapped with the Rehearsal subnet. A similar setup is present on your target data center. Both the subnets having the purpose as Production are paired.
Now when you perform the migrate operation, since the subnets having purpose as Production are paired, the virtual machine is migrated with appropriate network settings.
For example, a virtual machine has IP address 10.20.30.40 and is part of subnet 10.20.30.0/24 on source data center. This subnet is paired with another subnet 10.20.50.0/24 in the target data center. Hence when the virtual machine is migrated, its IP address is automatically changed to 10.20.50.40 on the target data center.
In the target data center, we have mapped the Production subnet to the rehearsal subnet. Hence when you perform the rehearsal operation, the rehearsal virtual machine is mapped on the rehearsal subnet.
For example, in your source data center you have two subnets (ProdSN1 10.20.30.0/24) with Production as the purpose and (ProdSN2 10.20.40.0/24) with rehearsal as the purpose. The Production subnet is mapped with the Rehearsal subnet. A similar setup is present on your target data center (RecovSN1 10.20.50.0/24 with Production as the purpose and (RecovSN2 10.20.60.0/24). Both the subnets having the purpose as Rehearsal are paired.
Note:
Rehearsal subnet should be configured such that it is isolated from the production network.
You may want to perform Rehearsal operations in only one of the data centers. In that case, you can have network objects (for example, subnet) with purpose as Rehearsal in only that data center. If you map network objects with purpose as Rehearsal later, you need to edit the resiliency group with or with option.