Using DHCP with RRAS (MCP Series)
When Remote Access Service (RAS) uses Dynamic Host Configuration Protocol (DHCP) to obtain IP addresses for dial-in clients, only the IP address from the DHCP lease is passed to the RAS client. Other options in the DHCP scope are not.Source
RAS servers can obtain IP addresses for remote clients from a dynamic host configuration protocol (DHCP) server. DHCP servers provide static and dynamic IP address allocation on a large network. You should select this option if a DHCP server is available.
When the RAS server starts up with the option to Use DHCP to assign remote TCP/IP addresses, it makes several DHCP requests in advance and caches the DHCP leases that it will need for dial-in clients.