DHCP static lease reservations



  • At work, I commonly bring up a new box, then convert its DHCP lease to a reservation.    This seems to be impossible to do with pfsense, but it would sure be handy.  For some reason, DHCP Static Reservations can not be in the same block as DHCP dynamic addresses.


  • LAYER 8 Global Moderator

    And what does have to do with creating a reservation??  Once it has a lease - click the little button and to make a reservation for that mac

    So lets say your scope is .100 to .200, it comes up dhcp and gets .104 – you create a reservation for .99 or .201 -- what is the problem, when it goes for renew or you reboot it or, or pull the network plug on it it asks for dhcp again and gets its reservation.



  • This design decision forces the administrator to think a little before assigning reservations. In my opinion that is only a good thing as it is encouraging using good practises, like grouping similar nodes together in sub-ranges. Thinking a little about each reservation in the end gives us a less messy network, which in turn saves us from confusion later.

    By the way, it is explained in the book pfSense: The Definitive Guide (included in the Gold subscription, very much recommended) that a reservation isn't really a reservation but merely a preference. If someone else has "borrowed" the "reserved" address, an address from the dynamic pool is instead used to prevent conflicts.


  • LAYER 8 Global Moderator

    Sounds right to me - like the Seinfeld episode where he makes a car reservation.

    Youtube Video


Log in to reply