Netgate Discussion Forum
    • Categories
    • Recent
    • Tags
    • Popular
    • Users
    • Search
    • Register
    • Login

    WAN fails to keep DHCP address on cable modem reboot

    Scheduled Pinned Locked Moved General pfSense Questions
    35 Posts 3 Posters 3.7k Views
    Loading More Posts
    • Oldest to Newest
    • Newest to Oldest
    • Most Votes
    Reply
    • Reply as topic
    Log in to reply
    This topic has been deleted. Only users with topic management privileges can see it.
    • 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)

      1 Reply Last reply Reply Quote 0
      • 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?

          1 Reply Last reply Reply Quote 0
          • 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?

            1 Reply Last reply Reply Quote 0
            • 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

              B 1 Reply Last reply Reply Quote 0
              • 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.

                1 Reply Last reply Reply Quote 0
                • 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

                  B 1 Reply Last reply Reply Quote 0
                  • 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.

                    1 Reply Last reply Reply Quote 0
                    • 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

                      B 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:

                        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)

                        B 1 Reply Last reply Reply Quote 0
                        • 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)

                            1 Reply Last reply Reply Quote 0
                            • 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?

                              1 Reply Last reply Reply Quote 0
                              • 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

                                B 1 Reply Last reply Reply Quote 0
                                • 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)

                                    B 1 Reply Last reply Reply Quote 0
                                    • 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.

                                        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:

                                          only have igb0 through igb3, that's all I need?

                                          As @stephenw10 says too

                                          "prtsc" shows in my example one I350-T4 and one I350-F4 are configured so it shows 0 to 7.

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

                                          1 Reply Last reply Reply Quote 0
                                          • First post
                                            Last post
                                          Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.