Can't connect to VPN through ec2

I have created a VPC (private and public subnet) and VPN connection with the AWS wizard.

Unfortunately, I can't connect to the host in the VPN outside AWS. When I try, I get a timeout.

I have created an ec2 instance in the private subnet which normally see the VPN. I have checked this link (http://ift.tt/1DOuRjg) and all the configuration seems good in VPN side.

Just one thing, we have configured only one tunnel, we can't configure two tunnel. In the AWS console, I see two tunnels down (see attachment). So I have three questions:

Why I have two tunnels by default ? Which tunnel is used by default ? How can I debug the connection to see where I have the problem ?

Thanks for your help.