When you configure a DHCP reservation, the IP address associated to the MAC address of the potential DHCP client must be within the actual configured DHCP address pool and should not be excluded. If the IP address assigned to the DHCP reservation is outside of the DHCP address pool or excluded, the DHCP client will not receive a response from the DHCP server. This will most likely will result in the client self-assigning an Automatic Private IP Addressing (APIPA) IP address.
The range for APIPA IP addresses are: 169.254.0.0 -169.254.255.255
The APIPA netmask is: 255.255.0.0
To resolve this, be sure to created a DHCP Reservation using an IP address that lies within your valid DHCP pool.