SCALANCE M-800 as DHCP server   
2.2 Specifying DHCP options 
  SCALANCE M-800 Getting Started 
86  Getting Started, 06/2015, C79000-G8976-C337-04 
2.  In "Pool ID", select "1". Enter "1" in "Option Code". 
3.  Click "Create". A new row is created in the table. The subnet mask 255.255.255.0 is 
entered automatically. 
4.  Click "Set Values". 
5.  Enter "3" in "Option Code". Click "Create". A new row is created in the table. 
6.  Since the device will be used as a gateway, enable "Use Interface IP". Click "Set Values". 
The IP address of the device is entered automatically as the value. 
7.  Enter "6" in "Option Code". Click "Create". A new row is created in the table. 
8.  Since the device will be used as a DNS relay, enable "Use Interface IP". Click "Set 
Values". The IP address of the device is entered automatically as the value. 
9.  Enter "42" in "Option Code". 
10.Click "Create". A new row is created in the table. 
11.In "Set Values", enter the IP address of the NTP server in hexadecimal notation. 
 
The DHCP options are configured. If a DHCP client requests an IP address, in addition to 
the host IP address, it also receives the information entered in the DHCP options.