Find more details in the AWS Knowledge Center: https://aws.amazon.com/premiumsupport/knowledge-center/check-vpn-tunnel-status/
Ben, an AWS Cloud Support Engineer, shows what you can check If traffic isn’t passing over your VPN on the AWS side. There are a few steps you can take to get it back up. The steps will be different depending on whether you are running a static VPN or BGP VPN.
Publisher: Amazon Web Services
You can watch this video also at the source.