Site to site VPN FortiGate to Cisco router

[galal2010]

Dears 

i tried to configure site to site VPN between two sites 

site1 is fortigate firewall with static IP 

site 2 cisco router c800 connected to internet through 3G router with no static IP  and Public IP serve more than customer  internet is shared 

is it possible ?

[adambomb1219]

Depends.  Is the 3G provider allowing IPSec packets?  I would set the C800 router to be imitator only and the FortiGate to responder only.  

[Toshi_Esumi]

Of course it's possible if the C800 supports IPsec. Either use IKE1 aggressive mode or IKE2 dynamic. Make sure NAT Traversal is enabled.

We stopped deploying C8xx about 10 years ago but at that time it required a license (SEC-K9?) to have IPsec if I remember correctly.

Toshi

[Rajan_kohli]

Hi,

it is possible unless there is no license issue on c800
you can refer to this link: https://docs.fortinet.com/document/fortigate/7.2.5/administration-guide/250464/cisco-gre-over-ipsec-...

Thanks

Rajan