Last night I experienced a particular interesting issue connecting a Cisco ASA device the Amazon VPC VPN module. This tunnel had already been configured and was operating normally there were some additional configuration changes made on the ASA side but nothing that would bring the tunnel down completely. What my experience was that the VPC VPN Tunnel dashboard was now showing both tunnels in Green. The traffic was now not routing we tried reverting back to the original config still the same problem. We also tried rebooting the Cisco ASA device completely and was still seeing the VPC Dashboard showing both tunnels as up. As a last ditch effort we decided to go ahead and delete the existing tunnel from the Amazon side and then recreated the tunnel again using the VPN WIzard. Once that was completed the network communication was re-established and traffic was going across normally. We also updated the config with the original changes we had made earlier before the original VPN Tunnel went down and the tunnel was still up and stable after these changes. In short if you experience this in your environment to save you some time it may be best just to delete the existing tunnel and recreate again.