Moving a service physically from one region to another represents a networking challenge, especially if applications have hard-coded IP addresses. Network address space and IP address assignment considerations require that you either use the same IP address or a different IP address at the recovery region. In many situations, you assign new IP addresses because VLANs do not typically stretch between regions.
This design uses NSX for vSphere to create virtual networks called application virtual networks (AVNs). In AVNs, you can place workloads using a single IP network address space that spans across data centers. AVNs have the following benefits:
Single IP network address space providing mobility between data centers
Simplified disaster recovery procedures
After a failover, the recovered application is available under the same IPv4 address.
The IPv4 subnets (orange networks) are routed within the vSphere management network of each region. Nodes on these network segments are reachable from within the SDDC. IPv4 subnets, such as the subnet that contains the vRealize Automation primary components, overlap across a region. Make sure that only the active IPv4 subnet is propagated in the region and beyond. The public facing Ext-Mgmt network of both regions (grey networks) is reachable by SDDC users and provides connection to external resources, such as Active Directory or DNS. See Application Virtual Network.
NSX Edge devices provide the load balancing functionality, each device fronting a network that contains the protected components of all management applications. In each region, you use the same configuration for the management applications and their Site Recovery Manager shadow. Active Directory and DNS services must be running in both the protected and recovery regions.