DHCP Reservations and Exclusions
- disadvantage of standard dynamic assignment:
- does not guarantee any given client will retain the same IP address over time
- useful for some clients to keep same IP address
- e.g., network printer or wireless access point
- one solution:
- can configure static assignments using IP addresses outside DHCP scope
- can also assigned addresses from a specially configured exclusion range
- con: lose advantage of centralized configuration management
- another solution:
- create a reservation
- is a mapping of MAC address or interface ID to a specific IP address within the DHCP server’s address pool
- when DHCP server receives a request from the given interface, always provides the same IP address
- referred to as static or fixed address assignment
- an automatically allocated reservation refers to an address that is leased permanently to a client
- distinct from static allocation as the administrator does not predetermine which specific IP address will be leased