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With SDN-C deployed in a geo-redundant fashion (see Installation Deployment of Geo-Redundant SDN-C), activity can be switched from one site to the other in one of two ways:
- manually by the site operator
- automatically via PROM, based on health of active site
In either case, after the failover has been completed and the sites have transitioned from 'standby' to 'active' and vice versa, the DNS entry for the SDN-C deployment is updated (see Geo-Redundant SDN-C DnsSwitch) in order to provide clients with the correct SDN-C target for their messaging.
Manual (forced) failover
The manual option would be utilized by site operators wishing to force activity to a particular site so that they may proceed with performing maintenance or other activities on the other site without impacting service. Prior to carrying out this activity, it is suggested that the current role of the site(s) be determined (see SDN-C Site Role Detection).
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