@Shashank Kapoor , Unfortunately there is no option to set idle timeout in Route based VPN gateway. Also, automatic reconnection of the flow cannot be achieved here after an idle timeout likewise in policy-based VPN. For now, the best bet is to work with your client machine to achieve this feature. To help you further, I would be sharing a third-party document where client configuration is mentioned. Please be advised that you can try the instructions first on a trial node which is in non-prod env to avoid any kind of downtimes that may occur.
Disclaimer: This response contains a reference to a third-party document. Microsoft is providing this information as a convenience to you. Microsoft does not control these sites and has not tested any software or information found on these sites; therefore, Microsoft cannot make any representations regarding the quality, safety, or suitability of any software or information found there. There are inherent dangers in the use of any software found on the Internet, and Microsoft cautions you to make sure that you completely understand the risk before retrieving any software from the Internet.
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