VPN tunnel between SCALANCE M-800 and S612   
3.3 Secure VPN tunnel with certificates 
  SCALANCE M-800 Getting Started 
130  Getting Started, 06/2015, C79000-G8976-C337-04 
4.  Click on the "HTTP" tab in the content area. 
 
5.  Click on the "Load" button beside "IPSecCert" or "X509cert". The dialog for loading a file 
is opened. 
Navigate to the remote certificate. 
6.  Click the "Open" button in the dialog. 
The file is now loaded on the device. After loading successfully, confirm the next dialog 
with "OK". 
7.  Repeat steps 5 and 6 for the PKCS12 file. 
The certificates are loaded. With "Security" > "IPSec VPN" > "Certificates", you can display 
the certificates. The loaded certificates must have the status "valid".