DHCPServer leases IP address to the client in the following order of precedence.
- Checks for scopes available/defined for the subnet from which the client request has come. If available
- Checks for any reservation, if defined issues the reserved IPaddress. If not
- Checks for any free IPaddress within the scope range defined excluding the exclusions.
The above shows us clearly that reservation takes the precedence than exclusion. For example, A scope is defined with an reservation and the reserved IPaddress falls within the exclusion range. Still the DHCPServer will lease the IPaddress to the client even though the reserved IPaddress is excluded from the scope.
DHCP-NAP | Microsoft