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A new 'reachability' timer has been added to the connection manager config. Connectivity Manager (CMCM2) config. CM2 is responsible for detecting outages on the WAN/uplink interface(s) and for updating the is_used for the LTE interface when there is a WAN link reachability failure.
LTEM executes the switchover to LTE when the is_used field for LTE is set to true. Once the switchover is triggered, LTEM updates the IP rules to direct traffic to the LTE interface. In the background, connection manager CM2 periodically checks reachability over the WAN interface. If the WAN interface is back 'up', connection manager CM2 sets the is_used field for LTE to false. This triggers LTEM to update the IP rules to direct the traffic back to the WAN interface.
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