[slimo]

I succeeded to be able to authenticate with certificates.
Like I said early: I had to go to the FW object, VPN sheet, then add a certificate on the list. This will generate a certificate request. I took that request to my Microsoft Enterprise CA and I submitted the request. With the reply, I gone back to my FW and completed the certificate request. Voila that 's alll

PS: be sure also to define the external CA in OPSec

Slimo