Notification if DHCP-pool gets depleted? (pf 2.1.5)

  • Hi!

    Got a case where I'm not really sure if the address pool is big enough.

    So the questions:

    • Can I get a Notification (the built in pf-function) when the pool of addresses is depleted?

    • What should I look for in the DHCP-log?

    • Any monitoring I could use to get a better picture of the DHCP leases?


  • Rebel Alliance Developer Netgate

    There isn't a way to be notified currently, but what you're looking for in the DHCP log would be something along the lines of "no free leases"

    Similar to:

    dhcpd: DHCPDISCOVER from xx:xx:xx:xx:xx:xx via em0: network y.y.y.0/24: no free leases

    There aren't any monitoring options for pool utilization currently.

  • I'm noob here it feels like. Can I see further back in dhcpd-log? Can find the log file.

  • The webGUI log display show however many lines you have set it to display.
    The whole log is in /var/log/dhcpd.log
    From command line:

    clog /var/log/dhcpd.log

    will spew out all the content.
    You can "grep" for what you like.

  • Thank you!
    Of course in /var/log …  ::) But no "no free leases" found in the file.

    Though, I could only see like 2 days back, the logs are trunked at 512KB it looks like. Anyway possible to increase this? Googled a bit on this but didn't find what, where or how to do it.

    Next step is to figure out a way to trigger some kind of alert if it runs out of addresses.

  • Rebel Alliance Developer Netgate

    If you are on 2.2, the size of the log file may be increased on the Settings tab under Status > System Logs.

  • Thank you sir! A great incentive to upgrade to 2.2.

    I have to convince the customer of that this is a good thing to do now. Currently running 2.1.5 with a couple of VLAN, site-to-site IPSEC and OpenVPN connections.
    Upgrade and at the same time take them from a /24-subnet to a /16. Internal address space is for the moment and i don't see anything that's in the way for that to become /16.