Availability zones and regions have different purposes. Availability zones protect against failures of individual hosts. Regions provide disaster recovery of the entire SDDC. This design deploys a protected region with one or two availability zones and recovery region with a single availability zone.

Availability zones

An availability zone is the fault domain of the SDDC. Multiple availability zones can provide continuous availability of an SDDC, minimize downtime of services, and improve SLAs.


Regions provide disaster recovery across different SDDC instances. Each region is a separate SDDC instance. The regions have a similar physical layer and virtual infrastructure designs but different naming. The SDDC in this validated design contains two regions.


A hub refers to the centralized provisioning and monitoring components of the SDDC. A hub can be dedicated to ROBO sites (depending on the number of ROBO connections required) or part of the VMware Validated Design for SDDC and, in either case, has the capability for failover between regions in the event of a disaster or for disaster avoidance.

Remote Office and Branch Office

A location used to support specific services such as manufacturing, hospitals, or call centers. These locations require minimal workload deployment and have hardware located in space constrained rooms.

The identifiers follow United Nations Code for Trade and Transport Locations(UN/LOCODE) and also contain a numeric instance ID.

Table 1. Availability Zones and Regions in SDDC


Availability Zone and Region Identifier

Region-Specific Domain Name

Region Description




Availability Zone 1 in San Francisco, CA, USA-based data center




Availability Zone 2 in San Francisco, CA, USA-based data center




Los Angeles, CA, USA-based data center

Table 2. Regions in Remote Office and Branch Office (ROBO)

ROBO Region Identifier

ROBO Description


New York City, NY, USA-based Remote Office and Branch Office


ROBO identifiers vary according to the locations in your deployment.

Table 3. Design Decisions оn Availability Zones and Regions

Decision ID

Design Decision

Design Justification

Design Implication


Deploy the hub using two regions.

Supports multi-region failover capabilities while sustaining centralized provisioning and monitoring of ROBO sites.

Having multiple regions requires an increased solution footprint and associated costs.