Why C8000v cannot establish sdwan bfd session ?

[John.lc]

Hi  experts.

I have newly deployed an SDWAN environment.
The controllers are all version 20.16.1
The edge devices use C8000v 17.6.1, and there are 2 C8000v in the network.
All controllers and edge devices are in the same LAN.
The edge devices can be registered to vmanage normally, but there is no BFD session between C8000v edge devices, and there is a control link with the controller.

What is the reason for this? Is it because of the license? Or is there a problem with my configuration?
Thank you

[Kanan Huseynli · Accepted solution]

Hi,

most probably routers have the same site-ID. By default, the same site routers don't establish BFD between each other.

[John.lc]

Ho, I really dug a big hole for myself without realizing it.
Now the problem is perfectly solved, thank you for your help.