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    WAN fails to keep DHCP address on cable modem reboot

    Scheduled Pinned Locked Moved General pfSense Questions
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    • stephenw10S
      stephenw10 Netgate Administrator
      last edited by

      If it's a link negotiation issue (it keeps re-negotiating) setting it fixed may remove that. But the other end must also support a fixed speed/duplex link for that to work.

      Steve

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      • B
        BlankSpace
        last edited by

        It is set to auto, I have not tried to manually set it to 1000 Full. I will try it once I have an open window to do some tinkering.

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        • DaddyGoD
          DaddyGo @BlankSpace
          last edited by

          @BlankSpace said in WAN fails to keep DHCP address on cable modem reboot:

          I believe it is already set to automatic by default.

          these are usually automatic by default...

          your two devices (modem / pfSense eth.ports) probably there are different - different eth. controllers (Intel, Realtek, etc.)

          these controllers often have a trial with speed matching - especially Realtek stuff and thus are placed in a speed matching loop

          Cats bury it so they can't see it!
          (You know what I mean if you have a cat)

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          • B
            BlankSpace
            last edited by

            I forced the speed at 1000 and duplex at full, bounced the WAN interface and it came back up and grabbed the IP with no issues. This may be the solution...

            DaddyGoD 1 Reply Last reply Reply Quote 0
            • stephenw10S
              stephenw10 Netgate Administrator
              last edited by

              Nice. You still get the expected throughput?

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              • B
                BlankSpace
                last edited by

                Well, I am not sure. I thought it looked like my RTT and RTTsd increased a little and then I did some speedtests from the pfs command line and they were all over the place. So it is possible my throughput suffered, or just busy cable at this time of the night. I will need to try some speedtests at different times to confirm.

                However, since it seemed to solve the problem by adjusting the negotiation, what other workarounds would there be if indeed my throughput suffered from forcing negotiation?

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                • stephenw10S
                  stephenw10 Netgate Administrator
                  last edited by

                  If you set a fixed speed at one end you would usually have to set it fixed at both ends. Otherwise the other side might default to 100Mb half or something.
                  Putting a switch in between would also remove negotiation issues between those two specific devices as both then negotiate with the switch instead.

                  Steve

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                  • B
                    BlankSpace @stephenw10
                    last edited by

                    @stephenw10

                    Ah, yes I forgot about that option. Any reason it only happens if the interface is disabled or loses the link with the cable modem when the modem reboots? When I restart pfs there are no issues.

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                    • stephenw10S
                      stephenw10 Netgate Administrator
                      last edited by

                      Hmm, well that might imply it negotiates differently when the modem comes up.

                      If your modem really is just a modem and doesn't have a switch IC then I would expect to see a speed/duplex mismatch if you set pfSense to fixed. That usually kills throughput as you get loads or errors on the interface.

                      Adding a switch in between would be a better test in that situation.

                      Steve

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                      • B
                        BlankSpace @stephenw10
                        last edited by BlankSpace

                        @stephenw10

                        I had two modems that did this, the first was the cable company provided Arris CM8200. The Arris modems would actually go into a boot loop everytime pfs dropped the IP and tried to renegotiate. They would actually lose signal on the cable end and just keep looping until pfs was restarted.

                        Then I purchased my own Netgear Nighthawk CM1200. The Netgear has 4 ports but it is not a switch per se, it is for link aggregation and multiple IP address.

                        I just tested speed this morning when manually forcing 1000/full and it did indeed go down, by alot, each time I did the speedtest.

                        I do have some spare switches laying around that I will try. It's not really too big of an issue because I can always restart pfs and in 60 seconds its back up anyway. But sometimes I want to quickly bounce the cable modem to clear the logs and not have to restart pfs.

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                        • stephenw10S
                          stephenw10 Netgate Administrator
                          last edited by

                          It would confirm it's a link problem of some type though. Adding a switch is a good test a least.

                          Steve

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                          • DaddyGoD
                            DaddyGo @BlankSpace
                            last edited by

                            @BlankSpace said in WAN fails to keep DHCP address on cable modem reboot:

                            This may be the solution...

                            Due to the plenty of "noname" chip (PHY, eth. magnetics, PCB. etc.) manufacturers, unfortunately we encounter more and more of this problem.(Free after... @chpalmer https://www.badmodems.com/)

                            (the bad principle lately is that the modem should be cheap and not really the function is the point)

                            It's good if your test was successful. 😉

                            you may still be able to refine your settings with these parameters (Protocol timing)

                            91db0bc8-1720-4dc5-b8d5-584caa080157-image.png

                            Cats bury it so they can't see it!
                            (You know what I mean if you have a cat)

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                            • B
                              BlankSpace @DaddyGo
                              last edited by

                              @DaddyGo

                              Thanks, I will need to read up on those settings, I have never messed with them before and do not know what each does.

                              DaddyGoD 1 Reply Last reply Reply Quote 0
                              • DaddyGoD
                                DaddyGo @BlankSpace
                                last edited by

                                @BlankSpace said in WAN fails to keep DHCP address on cable modem reboot:

                                Thanks, I will need to read up on those settings,

                                Okéééé:
                                https://docs.netgate.com/pfsense/en/latest/book/interfaces/ipv4-wan-types.html

                                Cats bury it so they can't see it!
                                (You know what I mean if you have a cat)

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                                • B
                                  BlankSpace @stephenw10
                                  last edited by BlankSpace

                                  @stephenw10

                                  So I put a new cheap unmanaged gigabit switch (Netgear GS205) in between pfs and the modem. And it does the same thing, pfs can't get a stable link, keeps dropping and connecting in a loop. If I restart pfs, no issues.

                                  During this time, this is being displayed on the console: "config_aqm Unable to configure flowset, flowset busy!"

                                  Can it be related to the limiters I have created?

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                                  • stephenw10S
                                    stephenw10 Netgate Administrator
                                    last edited by

                                    Yes. It could be.
                                    Though that could also just be a symptom of the limiter queues filling when the link goes down.

                                    Try removing them.

                                    You might also disabling flow control on igb3 if it is enabled.

                                    Steve

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                                    • B
                                      BlankSpace @stephenw10
                                      last edited by

                                      @stephenw10

                                      I'm basically running upload and download limiters using FQ_CODEL for bufferbloat. I just followed the documentation in a video I found.

                                      igb3 is my WAN interface.

                                      DaddyGoD 1 Reply Last reply Reply Quote 0
                                      • DaddyGoD
                                        DaddyGo @BlankSpace
                                        last edited by

                                        @BlankSpace

                                        @stephenw10 "You might also disabling flow control on igb3 if it is enabled."

                                        in addition I would even disable EEE (in loader.conf.local)

                                        0275a0ef-ebfc-4010-a856-cc66b6459890-image.png

                                        Cats bury it so they can't see it!
                                        (You know what I mean if you have a cat)

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                                        • B
                                          BlankSpace @DaddyGo
                                          last edited by

                                          @DaddyGo

                                          Thanks, I created loader.conf.local in /boot and added those lines. Safe to assume if I only have igb0 through igb3, that's all I need?

                                          DaddyGoD 1 Reply Last reply Reply Quote 0
                                          • stephenw10S
                                            stephenw10 Netgate Administrator
                                            last edited by stephenw10

                                            Yes. It won't hurt adding more but it won't do anything except maybe log an error since you only have 4 NICs, those further OIDs don't exist.

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