WAN interface drops external IP (wont re-aquire after link loss)

  • I thought about where to put this post, but it likely is a hardware specific issue.
    I think.

    Anyway, after link loss for any reason on the UBEE DOCSIS3 modem i use, the PFsense external WAN interface has stopped re-aquiring the DHCP assigned IP automatically like it used to.

    This may be new as of the latest update, but I am unsure.

    I can re-aquire the IP by disabling and re-enabling the interface from the GUI.

    What are some of the typical reasons for this?

  • Netgate Administrator

    A typical problem here is that some cable modems start handing out local IPs (192.168.X.X) when they loose their connection. pfSense will sometimes acquire that local IP and then not re-try for a real address later since the modem is still responding on the local address.

    Check what IP pfSense is using when the modem looses link.


  • Not to hijack, but there have been a few (4-5 come to mind) reports of cable modems not handing out DHCP addresses to pfSense installations.  I actually had the same thing happen to me this morning for the first time in months.  I had to reboot my cable modem because I was having Internet issues, and my static business router came on and started working like a charm, but the residential dynamic interface never pulled an IP address until I click on the "Release" / "Renew" button in Status->Interfaces.

    My residential IP address rarely ever changes, but when it does pfSense gracefully fails to the business WAN line but on occasion it never renews properly or automatically on the residential side.

    I also changed the gateway monitoring address to to force the link to refresh even if it got a internal IP assigned to it.  The dashboard widget was gray with a note about acquiring status or something like that.

    Weird but a few (again 4-5) have noted the same experience.

  • Take a look at the release notes for the 2.0.3 update.

    I just installed it.

    The reason I did this, was because it mentioned something about "forgetting" DHCP addresses instead of renewing.

    I'm hoping this will resolve the issue.

    I welcome any opinions on this resolved issue versus mine.

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