This topic explains the behavior of the default gateway when importing DHCP.
When you create an IPv4 network in Address Manager, by default, the first address after the network ID is allocated as the default gateway address. If you do not explicitly define the Router option in Address Manager, then the default gateway address is deployed to a Managed Windows server as the scope-level Router 003 option. If you define the Router option in Address Manager, the address defined within the option overrides the default gateway option.
Importing the Router Option
During the import of a DHCP scope, the default gateway address allocation is not set as a result of the import: only the DHCP Router option (if configured) is imported. If the IP network existed in Address Manager before you imported the corresponding scope, the default gateway address is removed during the import. For more details on scopes, refer to Windows Scopes, Split-Scopes, and Superscopes.