The default timeout is 30 seconds. Therefore the Desktop login client will try the first listed Defender Security Server (DSS) configured in the Gina configuration, wait 30 seconds and then try the next DSS. If the next DSS is also not available, then the client will wait another 30 seconds before trying the next DSS in the list. Note that this timeout period is not configurable.
Enhancement request TF00723701 has been submitted to Development for consideration in a future release of Defender to allow this timeout value to be configured.