Occasionally dropping DHCP

  • I'm running pfSense on a customer build device. Every so often it completely drops DHCP to every device connected whether it hardlined, wireless or even staticially assigned. Powercycling the device resolves this issue every time - but eventually will happen again.

  • @blucube

    What do you mean by "dropping"? Is the server not responding? Are all the devices failing at the same time?

    DHCP only does something in response to a client trying to get an address. It will then do nothing until the client renews around 1/2 or 2/3 the way through the lease time. This means that the clients will likely fail at different times.

  • @JKnott you're correct, the description is vaguely what is happening but likely the result of something happening I'm not entirety sure how to identify or explain at this time.


    Modem DMZplus
    pfSense Router
    Unmanaged Switch
    LAN/WAP devices

    Everything stops being able to communicate with the pfSense router at the same time and loses their DHCP lease respectively.

    As a result loses connection to internet, local server, cannot ping locally to any device, ip renew does not work.

    Manual power cycle always restores connectivity / IP Lease / Routing tables.

  • @blucube

    What devices are being power cycled? PfSense? The clients?

    One thing that can help solve this is Packet Capture. Run it, filtering on DHCP (port 67 or 68), and see what happens.

    You may want to download the capture to examine it with Wireshark.

  • Just the router. I'll have to start keeping note how often it happens. Feels like it's a month or two in between.

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