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

    Wireless clients lose ipv6 gateway

    Scheduled Pinned Locked Moved IPv6
    gatewayipv6radvd
    30 Posts 3 Posters 6.1k 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.
    • JKnottJ
      JKnott @sarkyscouser
      last edited by

      @sarkyscouser said in Wireless clients lose ipv6 gateway:

      I have dhcp6 on and RA set to assisted

      I use SLAAC, so no DHCPv6 server.

      PfSense running on Qotom mini PC
      i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
      UniFi AC-Lite access point

      I haven't lost my mind. It's around here...somewhere...

      S 1 Reply Last reply Reply Quote 0
      • S
        sarkyscouser @JKnott
        last edited by sarkyscouser

        @jknott I tried all the permutations of DHCP6 and RA modes and none worked until I cycled gateway monitoring.

        I could probably turn off DHCP6 now and go to umanaged RA mode but as it's working I am not touching it!

        M 1 Reply Last reply Reply Quote 0
        • M
          mfld LAYER 8 @sarkyscouser
          last edited by

          @sarkyscouser

          I have observed this, too and no combination of gateway monitoring, Unifi Multicast setting, DHCPv6 on or off made any difference. It appears to be an Android implementation issue where the device will go to power save mode and not refresh RA.

          Some references: 1

          2

          Looking at pfSense Router Advertisements section I see 3 areas of interest:

          Minimum RA interval (defaults to 5s)
          Maximum RA interval (defaults to 20s)
          Router lifetime (defaults to 3 x max, so max 60s)

          My hypothesis is that many (most?) Android firmware builds will not receive these multicast announcements when you put the device down.

          To power down the radio and save battery.

          With pfSense default settings my understanding of it is that this means if the device is not in the loop for more than 60 seconds the RA will expire and the device will assume there is no IPv6 router on the network. Why on earth it doesn't come back once you pick up the device and unlock its screen is a mystery to me but it seems to quite a number of people, regardless of Unifi or pfSense being in the equation.

          To test this hypothesis I will try two things:

          1. Use developer mode on an effected Android device to prevent sleep and see what happens.

          2. Set "Router Lifetime" to a high number. Higher than 12h. Let's say the user had a party got drunk, slept 10 hours. I want the device to still know there is IPv6 when they wake up after not being touched for 12 hours.

          Not sure the side effects of a super high Router Lifetime. I think if there is only one IPv6 router on the network and no HA setup involved it won't hurt. Perhaps anyone can chime in on that. There must be a reason why the pfSense defaults are rather low. Most Samsung Android devices will not check into WiFi every 60s when they are idle with screen off.

          TL;DR: I suspect the solution may be here somehow:

          ipv6.JPG

          M S JKnottJ 3 Replies Last reply Reply Quote 0
          • M
            mfld LAYER 8 @mfld
            last edited by

            Akismet won't let me edit so I need to reply to myself here:

            What makes me want to look at "Router Lifetime":

            HPE

            Broadcom

            TIL that pfSense UI will not let me set 12 hours. I can set a max of 9000 seconds (2.5 h). I will go ahead and test with that. As long as rhe device checks in with the network and gets a new RA broadcast in that time frame things should work.

            S 2 Replies Last reply Reply Quote 1
            • S
              sarkyscouser @mfld
              last edited by

              @mfld I understand your line of thinking but I managed to get my android phone (Nokia 8.1 running Android 11) to hold it's ipv6 connection info for 24 hours yesterday by unsetting gateway monitoring.

              This morning I decided to disable dhcp6 and set RA to unmanaged mode to see what happened and within 10 min my phone dropped the dhcp6 gateway and didn't re-establish it.

              So I'm going back to dhcp6 on and assisted mode and if that still works that's where I'm staying.

              S 1 Reply Last reply Reply Quote 0
              • S
                sarkyscouser @mfld
                last edited by

                This post is deleted!
                1 Reply Last reply Reply Quote 0
                • S
                  sarkyscouser @mfld
                  last edited by

                  @mfld said in Wireless clients lose ipv6 gateway:

                  Akismet won't let me edit so I need to reply to myself here:

                  What makes me want to look at "Router Lifetime":

                  HPE

                  Broadcom

                  TIL that pfSense UI will not let me set 12 hours. I can set a max of 9000 seconds (2.5 h). I will go ahead and test with that. As long as rhe device checks in with the network and gets a new RA broadcast in that time frame things should work.

                  @mfld please let us know how you get on with this, that might fix the issue with unmanaged mode.

                  1 Reply Last reply Reply Quote 0
                  • S
                    sarkyscouser @sarkyscouser
                    last edited by

                    @sarkyscouser OK so rather than going back to DHCP6 and assisted mode, I went into my WAN interface, clicked save and apply changes (without actually making any) and now it seems to be holding.

                    So from this experience, it appears that 2 things are necessary:

                    1. turn off gateway monitoring
                    2. whenever you make any changes to DHCP6 or RA mode, re-save and apply settings in WAN interface.
                    S 1 Reply Last reply Reply Quote 0
                    • S
                      sarkyscouser @sarkyscouser
                      last edited by

                      @sarkyscouser said in Wireless clients lose ipv6 gateway:

                      @sarkyscouser OK so rather than going back to DHCP6 and assisted mode, I went into my WAN interface, clicked save and apply changes (without actually making any) and now it seems to be holding.

                      So from this experience, it appears that 2 things are necessary:

                      1. turn off gateway monitoring
                      2. whenever you make any changes to DHCP6 or RA mode, re-save and apply settings in WAN interface.

                      Spoke too soon, gateway lost again :-(

                      1 Reply Last reply Reply Quote 0
                      • JKnottJ
                        JKnott @mfld
                        last edited by

                        @mfld said in Wireless clients lose ipv6 gateway:

                        It appears to be an Android implementation issue where the device will go to power save mode and not refresh RA.

                        I have 2 Android devices and I've had 4 others I no longer use. I have never seen that.

                        PfSense running on Qotom mini PC
                        i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                        UniFi AC-Lite access point

                        I haven't lost my mind. It's around here...somewhere...

                        S M 2 Replies Last reply Reply Quote 0
                        • S
                          sarkyscouser @JKnott
                          last edited by

                          @jknott said in Wireless clients lose ipv6 gateway:

                          @mfld said in Wireless clients lose ipv6 gateway:

                          It appears to be an Android implementation issue where the device will go to power save mode and not refresh RA.

                          I have 2 Android devices and I've had 4 others I no longer use. I have never seen that.

                          Beginning to think that this is a bug that needs raising. How best to debug via the logs first before I do that?

                          M 1 Reply Last reply Reply Quote 0
                          • M
                            mfld LAYER 8 @JKnott
                            last edited by

                            @jknott

                            Strange, isn't it. Maybe it's a combo of Unifi + Android + IPv6.

                            Here at this site all devices do it. They all lose IPv6 address if you put them down with their screen off and walk away for a bit. They won't reaquire it until you bounce the WiFi.

                            Moto G6 (Android 9), Oneplus 6T (Android 10), Samsung Note 20 Ultra 5G (Android 11), Samsung S20 (Android 11).

                            All seem to work fine now that Router lifetime in RA settings has been cranked up from default. Turned GW monitoring back on and it still works just fine. This is why this hasn't made it into redmine. Neither of us have anything conclusive that would make a useful bug report. But it is certainly real.

                            S JKnottJ 2 Replies Last reply Reply Quote 0
                            • M
                              mfld LAYER 8 @sarkyscouser
                              last edited by mfld

                              @sarkyscouser said in Wireless clients lose ipv6 gateway:

                              Beginning to think that this is a bug that needs raising. How best to debug via the logs first before I do that?

                              I would have dropped it into redmine long ago if I had a way to prove the issue. I can guarantee you right now they would just close it because it cannot be reproduced. Thousands of installs out there do not have this issue. We'd have to dig very deep. Packet capture everything from the device in your hand back to pfSense.

                              It may also depend on what apps one has installed. Apps can make the device listen for multicast.

                              This may be related:

                              Normally the Wifi stack filters out packets not explicitly addressed to this device. Acquring a MulticastLock will cause the stack to receive packets addressed to multicast addresses. Processing these extra packets can cause a noticeable battery drain and should be disabled when not needed.

                              1 Reply Last reply Reply Quote 0
                              • S
                                sarkyscouser @mfld
                                last edited by

                                @mfld said in Wireless clients lose ipv6 gateway:

                                @jknott

                                Strange, isn't it. Maybe it's a combo of Unifi + Android + IPv6.

                                Here at this site all devices do it. They all lose IPv6 address if you put them down with their screen off and walk away for a bit. They won't reaquire it until you bounce the WiFi.

                                Moto G6 (Android 9), Oneplus 6T (Android 10), Samsung Note 20 Ultra 5G (Android 11), Samsung S20 (Android 11).

                                All seem to work fine now that Router lifetime in RA settings has been cranked up from default. Turned GW monitoring back on and it still works just fine. This is why this hasn't made it into redmine. Neither of us have anything conclusive that would make a useful bug report. But it is certainly real.

                                Yes I think the default RA settings are poor. Just done a quick bit of research:

                                https://techhub.hpe.com/eginfolib/networking/docs/switches/WB/16-01/5200-0135_wb_2920_ipv6/content/ch08.html
                                https://knowledge.broadcom.com/external/article/167985/ipv6-router-lifetime-in-router-advertise.html

                                and pumped up my default settings to:

                                Default valid lifetime: 655350
                                Default preferred lifetime: 604800
                                Minimum RA interval: 200
                                Maximum RA interval: 600
                                Router lifetime: 1800

                                and now my Android 11 device receives ipv6 DNS which is the first time that has happened.

                                If DHCP6 + assisted persists for 24 - 48 hours I'll try with no DHCP6 and unmanaged again and see what happens.

                                M 2 Replies Last reply Reply Quote 0
                                • M
                                  mfld LAYER 8 @sarkyscouser
                                  last edited by

                                  @sarkyscouser said in Wireless clients lose ipv6 gateway:

                                  Yes I think the default RA settings are poor. Just done a quick bit of research:

                                  To me it seems the defaults are sane for most enviroments and the different RA modes in pfSense's implementation of radvd work exactly as advertised. The issue with mobile devices is that they need to be sleeping and selective about what they will do when the screen is off. For IOS devices we don't see an issue when DHCP6 is on because the lease time is long enough and they just handle things differently.

                                  For Android there is no DHCP6 support and devices with aggressive power management will see the default RA expiry of 60s, go to sleep, not refresh anything and then the timer expires. But I don't understand why the devices do not reaquire IPv6 when the user picks them up and unlocks the screen. radvd should broadcast in the next 5-20 seconds, the device should see that and process it. I don't get it. Above my paygrade.

                                  Router lifetime seems to do the trick here. Had a Samsung S10 screen locked and put away for 2 hours, picked it up and its fine.

                                  1 Reply Last reply Reply Quote 0
                                  • M
                                    mfld LAYER 8 @sarkyscouser
                                    last edited by

                                    @sarkyscouser said in Wireless clients lose ipv6 gateway:

                                    Default valid lifetime: 655350
                                    Default preferred lifetime: 604800
                                    Minimum RA interval: 200
                                    Maximum RA interval: 600

                                    I do not think you need to mess with these. The defaults are fine. Just the Router Lifetime default seems to be too low. Let me know how this works out for you.

                                    S 1 Reply Last reply Reply Quote 0
                                    • S
                                      sarkyscouser @mfld
                                      last edited by

                                      @mfld said in Wireless clients lose ipv6 gateway:

                                      @sarkyscouser said in Wireless clients lose ipv6 gateway:

                                      Default valid lifetime: 655350
                                      Default preferred lifetime: 604800
                                      Minimum RA interval: 200
                                      Maximum RA interval: 600

                                      I do not think you need to mess with these. The defaults are fine. Just the Router Lifetime default seems to be too low. Let me know how this works out for you.

                                      If I only increase the router lifetime my android 11 device doesn't pick up ipv6 dns addresses so going to see how these settings pan out.

                                      S 1 Reply Last reply Reply Quote 0
                                      • S
                                        sarkyscouser @sarkyscouser
                                        last edited by

                                        @sarkyscouser said in Wireless clients lose ipv6 gateway:

                                        @mfld said in Wireless clients lose ipv6 gateway:

                                        @sarkyscouser said in Wireless clients lose ipv6 gateway:

                                        Default valid lifetime: 655350
                                        Default preferred lifetime: 604800
                                        Minimum RA interval: 200
                                        Maximum RA interval: 600

                                        I do not think you need to mess with these. The defaults are fine. Just the Router Lifetime default seems to be too low. Let me know how this works out for you.

                                        If I only increase the router lifetime my android 11 device doesn't pick up ipv6 dns addresses so going to see how these settings pan out.

                                        So it seems that iOS doesn't like those settings. Put them back to default and the router lifetime to 1800 and still no luck.

                                        Why is this soooo hard!!

                                        S 1 Reply Last reply Reply Quote 0
                                        • S
                                          sarkyscouser @sarkyscouser
                                          last edited by

                                          So it's the "Maximum RA interval" that was preventing my android 11 device from receiving ipv6 dns servers. I've upped that to 60 sec and router lifetime to 1800. Android seems to be OK as does Windows 10 but my 2 ipads can no longer connect via ipv6.

                                          I've removed all the dhcp6 leases in pfsense and reset both ipads but no joy. Guess something lease-related is cached on the ipads so I'll just have to wait for them to expire and hope that the situation resolves itself in time.

                                          For my setup I need dhcp6 + assisted mode, unmanaged is still useless for android even with an increased router lifetime.

                                          1 Reply Last reply Reply Quote 0
                                          • JKnottJ
                                            JKnott @mfld
                                            last edited by

                                            @mfld said in Wireless clients lose ipv6 gateway:

                                            Strange, isn't it. Maybe it's a combo of Unifi + Android + IPv6.

                                            That's exactly what I have here.

                                            Have you tried a notebook computer via WiFi and Ethernet to compare?

                                            PfSense running on Qotom mini PC
                                            i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.
                                            UniFi AC-Lite access point

                                            I haven't lost my mind. It's around here...somewhere...

                                            S M 2 Replies Last reply Reply Quote 0
                                            • First post
                                              Last post
                                            Copyright 2025 Rubicon Communications LLC (Netgate). All rights reserved.