Azure Private DNS zone resiliency
DNS private zones are resilient to regional outages because zone data is globally available. Resource records in a private zone are automatically replicated across regions.
The following figure illustrates the availability of private zone data across multiple regions.
In this example:
- The private zone azure.contoso.com is linked to VNets in three different regions. Autoregistration is enabled in two regions.
- A temporary outage occurs in region A.
- Regions B and C are still able to successfully query DNS names in the private zone, including names that are autoregistered from region A (ex: VM1).
- Region B can add, edit, or delete records from the private DNS zone as needed.
- Service interruption in region A doesn't affect name resolution in the other regions.
The example shown here doesn't illustrate a disaster recovery scenario, however the global nature of private zones also makes it possible to recreate VM1 in another VNet and assume its workload.
Azure Private DNS is an availability zone foundational, zone-reduntant service. For more information, see Azure services with availability zone support.