Fortigate vpn configuration between two fortigates with same subnet ip but not overlaping

[festradateng]

Hi,

We have two Sites, Site A and Site B already connected by telephone line(old), so they share the subnet ip address, now we want to have a VPN tunnel as a Backup with two Fortigate on each side, we cannot change the subnet ip address,  Configuring Site-to-site IPSec VPN in Central SNAT mode with overlapping subnets doesn't work because this will change to new IPs, which is the best solution for this?

[Yurisk · Accepted solution]

There are many details missing for the context, but not to start a thread of 20 posts, the answer to your question - if both sites have the same subnet but different IPs assigned to hosts in them, VXLAN between Fortigates may do the job, read about it in documentation.

[festradateng]

Hi Yurisk, thank you for your response, I tested VXLAN and this works, now it is possible to have the VXLAN as a backup of  the LAN connection?