What happens when a Standby Appliance gets activated CMS/GTO?

This article provides some example scenarios and working of Failover in CMS/GTO setup

When a standby appliance gets activated:

• Existing user sessions from failed appliances may be resumed on the newly activated appliance and will be allowed to continue until the sessions are either terminated by users or by timing out.

• SMA Tunnel clients, such as Connect Tunnel and Mobile Connect & CTDG will detect a connection failure and automatically reconnect to the GTO service.

• ActiveSync client requests will get directed to the standby appliance.

• On Active-Active Scenarioes failover will happen in few seconds.

• Web-based client applications will reconnect to the standby appliance when users refresh the browser Window and authenticate again.

Some of the example scenarios,

Scenario 1: One Active and one Standby Appliance

GTO working:  Standby appliance is guaranteed to activate 10 - 15 minutes after all designated GTO appliances lose communication with the Standby appliance. To reduce the Failover time, we need to add a CEM value.

Refer the below link for more inforomation :-

https://www.sonicwall.com/support/knowledge-base/how-to-reduce-failover-time-where-for-an-appliance-in-standby-mode-in-cms-gto/200524191923080/

Scenario 2:  Environment:

-One Active and one Standby Appliance in U.S (Note: A Minimum should have Two Active nodes (Active-Avtive) and one Standby node is recommended)

-One Active and one Standby Appliance in Europe

GTO Working: If the active device in U.S goes down, the connections will be directed to the active device in Europe and the standby device in U.S wouldn't become active since the Standby device waits for a response for 10 to 15 minutes before switching to the active state. 

Scenario 3: One Active and one Standby Appliance

Issue: CMS is down.

GTO working: This does not affect the GTO service and the active appliance continues to serve users request made to the GTO name.