S2S VPN from fortigate which is behind a Cisco ASR

[vnagula]

Hi Team,

I have very limited exposure and experience configuring firewalls and I'm completely new to using Fortigate products. However part of my new job requires working with and understanding Fortigate firewalls, setting up VPN's etc...so please excuse my ignorance!

We have a setup as shown in the Current.jpg file.

The internet terminates from the Fortigate and the MPLS terminates from the Cisco ASR. Now, our management decided to move the internet termination to the ASR. So, my Internet and MPLS would be terminating from the ASR. 

I was assigned to build a S2S tunnel from the Fortigate to a customer AWS site while the Internet link was still on the fortigate. So, i would like to know if i can still build the S2S tunnel from the fortigate when it is behind the ASR and do not have exposure to internet.

Request your suggestions with the configuration here.

Thanks a lot in advance.