Fortigate 5.2.8 to Cisco IOS Router (Dynamic WAN) - Unable to get it working

[Elderusr]

Hi All,

Fortigate 5.2.8 500D HA going to Cisco IOS Router. I attempted to use the following configuration site for my basic configuration however ran into a few snags, and I am unable to get the communication to function properly between them:

https://blog.webernetz.net/2015/02/02/ipsec-site-to-site-vpn-fortigate-cisco-router/ Diagram:

Fortigate (Static WAN) <-----> (Dynamic WAN) 3G Modem (192.168.0.1/24) <------> (192.168.0.250) Router (192.168.9.0/24) <---> LAN I have enabled IKE debug on the Fortigate, and see the requests leaving the Fortigate to the Cisco Device, however nothing comes in from the Cisco Device. When I turn on debug on the Cisco Device, I see it attempting communication, but to no avail. I am able to hit external sites/ect from the router otherwise.

Time is sync'd properly between the devices. NAT-T is enabled on both devices. Any other suggestions/comments would be appreciated.