I hope this is the right place to post, we have a client with multiple branches, We want to connect them together so that the remote sites can be managed with the domain controller, all sites have diffrent isp and none have static wan address except for the HQ, is there a way to configure this with a l2tp and ddns o

Hello!

I am not sure because I have never used an AD (or whatever) authentication through a VPN, but I think L2TP will work
If you only need to reach the HQ from the branches, I think you won't need to use DDNS because you dont need to set the clients IP anywhere, you just need to configure the L2TP Server on the HQ.

Regards!
Damián