DHCP leases question (deleting a dhcp lease manually)



  • Is there a way (in the GUI) to manually delete DHCP lease? The DHCP server seems to "remember" even the expired leases, but I would prefer if they were removed, or there was a way to delete them.



  • @LawnMowerGuy1:

    Is there a way (in the GUI) to manually delete DHCP lease? The DHCP server seems to "remember" even the expired leases, but I would prefer if they were removed, or there was a way to delete them.

    From my experience using other DHCP servers this is a GOOD thing.

    pfSense remembers the leases for much longer than the expiration time, this means that if you remove a computer from your LAN and leave it offline for a long time, and then reconnect it… it will probably receive the same IP address.  If pfSense needs those leases it will reassign them as needed, but if they are not needed it will leave them.

    This will prevent IP address conflicts and will also allow your port forwarding to work on computers that are not always on the LAN.

    The impact of this is a few KB of disk space used (insignificant) and almost no RAM or CPU overhead.  If you want it cleaned up for asthetic purposes then I would say you are circumventing legitimate functionality.

    I have my complaints about the DHCP implementation on pfSense, but this is not one of them.

    • C4colo


  • Ok - it was great to find this so what I just want to confirm is that this part of the 1.2RC3 DHCP server gui at the bottom - with "enable network booting"

    That is setting option 66 and 67 of DHCP. This company are about to turn up and I have to have this
      option bootfile-name "Thomson/ST2030S";
        next-server 10.10.0.1;

    Set to make the phones find the server and config.

    So just looking for reassurance.

    Also still wondering if asterisk is going to be able to connect outward through the firewall. In the past I didn't have much luck making Asterisk work through a firewall but there are traffic shaping options related to asterisk.

    These last weeks I have really been converted from ipcop and smoothwall - pfsense is really complete.

    Thanks

    Jnana



  • I know this topic is rather old and kind of unnecessary but just to clarify if someone is really interested in removing expired leases

    In the GUI, go to Diagnostics/Edit File and load /var/dhcpd/var/db/dhcpd.leases~

    Delete the leases you want removed, then hit Save.

    Do the same for /var/dhcpd/var/db/dhcpd.leases



  • @onhel

    Thanks for your info. Exactly what i was looking for :)



  • =O)



  • Hmmm Deleting all the leases shown in the two files did not work for me, a reboot does however, although clearly this is a less preferable fix!



  • As onhel wrote: Try to press save on the DHCP config page after deleting the files.

    You somehow have to trigger that the config gets reloaded.
    A reboot reloads the config. Pressing save does too.



  • I had same problem ….. pfSense DHCP remembers all leased IPs and won't releases them even though 1 machine have several leases .
    I changed the IP range, save it then put the old IP range back, save it again. That resolves my problem till next time  the DHCP runs out of IP again.



  • Hello, just wondering if it actually worked

    thanks



  • Verified.
    Deleting the lease content information in those two lease files and then pressing the Save button in the DHCP Server page does update the current DHCP lease listing in the GUI.



  • @pfman:

    I had same problem ….. pfSense DHCP remembers all leased IPs and won't releases them even though 1 machine have several leases .
    I changed the IP range, save it then put the old IP range back, save it again. That resolves my problem till next time  the DHCP runs out of IP again.

    Do i understand this correctly, if many PC have several leases and every ip is used there will be no more leases until i do whats described here.


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