Graceful restart timer (in seconds). This time indicates how long the the cached information needs to be retained when connectivity between the devices and overlay orchestrator is lost. The devices will flush the orchestrated information and the overlay orchestrator will flush the advertised information from the devices when the connectivity is not restored with in this interval. Value should be in the range 1 minute (60 seconds) to 7 days (604800) and default is 12 hours.