Dhcp range not using all ip address

  • Hello All,


    Had to change  CIDR on one of our two pfSense machines at our school buildgings due to the fact we were running out of ip addresses with the influx of mobile devices This is on the LAN interface for completeness.
    Previous setup was .

    Now: We needed to go for 1022 dhcp ip addresses,so I changed the dhcp server config to, make avaliable 1022 addresses.

    I made the dhcp range from

    I of course changed the LAN ip on the pfSense machine from to .
    For some reason none of the workstations never end up with the range of
    They all start out at,etc.

    Of course I have never run into this before,and I m not sure what could be the culprit here. I will attach my dhcp server config page here.
    (The wins  and dns server is at a different building via vpn to cut down on confussion here)

    Thank You,

  • LAYER 8 Global Moderator

    So these machines that are getting 192.168.1 addresses - I would assume they are just renewing their old lease that got from before you changed the scope.

    clear out all your lease info on pfsense, and make sure your clients do a release and then have them get a new lease.  Then they will pull from one side of the scope.  I do believe pfsense likes to hand out near the top of the scope vs the bottom.. So you prob get say as first and the .253 as next, etc.

    But only getting in the middle of your scope seems like your just renewing their old lease to me.

  • johnpoz,

    Thank you for the reply. What you explained makes perfect sense in regards to the workstations being assigned their previous ip address in the dhcp pool. I am not going to delete all the leases in the dhcp gui for now,,Had plenty of work getting ip range changed over on the DC and such.

    The idea of the dhcp server assigning from high to lowest numbers doesn't seem to be holding true. The mobile devices seem to be getting 192.168.2.x number and i see only one 192.168.3.x device so at least I know the range is going into the "3" range.
    I guess the only way we will ever know if the "0" range is used if the device count goes beyond ,,about 750 devices on the lan at one time.


Log in to reply