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    No LAN IPv6 address with Track Interface on WAN

    Scheduled Pinned Locked Moved IPv6
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    • A
      azaclauson
      last edited by azaclauson

      Thx for the trace.

      I did a packet capture from the pfSense diagnostics option and by comparing it to yours I think I found the problem. It looks like my ISP/modem doesn't support prefix delegation.

      no_prefix.png

      My next question is whether it's possible for pfSense to relay DHCPv6 requests to my modem but then still be able to route the traffic. I'll ask that as a separate question after I do a bit of research.

      Update: This question https://forum.netgate.com/topic/154835/ipv6-dhcpv6-leases-not-being-assigned-on-pfsense-lan-network seems to be my exact problem. That means the answer is no, there is no way to have a IPv6 on my LAN without my modem supporting IPv6 prefix delegation...

      The strange thing is that it did work at one point. I think what I did was set a static IPv6 on my LAN interface and enabled a DHCPv6 server on the LAN. I guess I just got lucky that the routing worked for a little while.

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

        @azaclauson said in No LAN IPv6 address with Track Interface on WAN:

        My modem has a DHCPv6 server with an address range of:

        Perhaps you can clarify on this. Is your modem in gateway or bridge mode? You want bridge mode to work with pfSense (or any other router). With my modem, I get a single /64 in gateway mode, which cannot provide a prefix for the LAN. In bridge mode, I get a /56 prefix, which can be split into 256 /64s on the LAN side.

        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...

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        • JKnottJ
          JKnott @azaclauson
          last edited by

          @azaclauson said in No LAN IPv6 address with Track Interface on WAN:

          I did a packet capture from the pfSense diagnostics option and by comparing it to yours I think I found the problem. It looks like my ISP/modem doesn't support prefix delegation.

          See my previous post. If you're getting address from the modem, and not from the ISP, then you're in gateway mode. You need bridge mode.

          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...

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          • A
            azaclauson
            last edited by

            @JKnott said in No LAN IPv6 address with Track Interface on WAN:

            See my previous post. If you're getting address from the modem, and not from the ISP, then you're in gateway mode. You need bridge mode.

            It's in gateway mode as far as I can tell.

            It's a pretty simple residential cable modem and there is no bridge option.

            It does have a DHCPv6 server that is allocating addresses on a /64 prefix. Any machine that connects to the same LAN as the modem gets a public IPv6 address. But because the modem doesn't do prefix delegation then my understanding is there's no way to allocate public IPv6 addresses on the pfSense LAN.

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

              @azaclauson said in No LAN IPv6 address with Track Interface on WAN:

              It's in gateway mode as far as I can tell.
              It's a pretty simple residential cable modem and there is no bridge option.

              If you post your ISP and modem model, someone may be able to advise on this. Or you could call support at your ISP. Also, DHCPv6 is normally not used on the LAN side. IPv6 generally uses SLAAC, where the router provides the prefix and the client adds the suffix. The suffix can be based on the MAC address or a random number. In addition, you will get a new privacy address every day, which lasts for a week.

              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...

              1 Reply Last reply Reply Quote 1
              • A
                azaclauson
                last edited by

                If you post your ISP and modem model,

                Virgin Media, Ireland (https://www.virginmedia.ie/)

                Virgin Media Hub 3.0 device information
                The information below shows current status of this Virgin Media Hub 3.0.
                Standard specification compliant : DOCSIS 3.0
                Hardware version : 5.01
                Software version : CH7465LG-NCIP-6.12.18.26-3p7-1-NOSH

                I am going to contact my ISP and see if I can get a /56 IPv6 prefix.

                IPv6 generally uses SLAAC, where the router provides the prefix and the client adds the suffix. T

                After further experimentation and reading answers like this one, https://networkengineering.stackexchange.com/questions/30136/ipv6-is-it-possible-to-use-a-64-block-when-you-have-multiple-routers, it still seems like it's not possible to have pfSense further subnet a /64 address on the WAN such that clients on the LAN interface can use IPv6, whether they get an address from DHCPv6 or SLAAC.

                What I found confusing on the pfSense GUI is when entering a static IPv6 address (and a few other places such as routing advertisements) the prefix can be set all the way down to /128. Almost everything I've read states that /64 is smallest the interface ID should be set.

                I guess the ability to go smaller than /64 is for Unique Local Addresses (fc00::/7) rather than Global Unicast addresses.

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

                  @azaclauson said in No LAN IPv6 address with Track Interface on WAN:

                  it still seems like it's not possible to have pfSense further subnet a /64 address on the WAN such that clients on the LAN interface can use IPv6

                  You should be able to, but you can't use DHCPv6-PD to provide it. You have to manually configure routing to do it.

                  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...

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                  • A
                    azaclauson
                    last edited by

                    You should be able to, but you can't use DHCPv6-PD to provide it. You have to manually configure routing to do it.

                    I realise the manual set up would break as soon as my ISP assigned my modem a different IPv6 address but as an exercise I tried to set up the manual routing. I failed to get a usable IPv6 address on my machine. The steps I took were:

                    1. The DHCP range allocated to my cable modem from my ISP is:
                      2a02:8084:6981:7880::/64

                    2. On the pfSense WAN interface that's connected to the modem I set a static IPv6 of:
                      2a02:8084:6981:7880:2e0:67ff:fe09:9b10/80. I'm able to ping a public Internet address.

                    : ping6 -S 2a02:8084:6981:7880:2e0:67ff:fe09:9b10 2606:db00:0:62b::2
                    PING6(56=40+8+8 bytes) 2a02:8084:6981:7880:2e0:67ff:fe09:9b10 --> 2606:db00:0:62b::2
                    16 bytes from 2606:db00:0:62b::2, icmp_seq=0 hlim=116 time=137.717 ms
                    
                    1. On the pfSense LAN interface I set a static IPv6 of
                      2a02:8084:6981:7880:2e1:67ff:fe09:9b11/80. I set the WAN interface link local address of fe80::2e0:67ff:fe09:9b10 as the LAN gateway address. I'm not able to ping a public Internet address.
                    : ping6 -S 2a02:8084:6981:7880:2e1:67ff:fe09:9b11 2606:db00:0:62b::2
                    PING6(56=40+8+8 bytes) 2a02:8084:6981:7880:2e1:67ff:fe09:9b11 --> 2606:db00:0:62b::2
                    ^C
                    
                    : netstat -rWn
                    Routing tables
                    Internet6:
                    Destination                       Gateway                       Flags       Use    Mtu    Netif Expire
                    default                           fe80::362c:c4ff:febf:b8cb%em0 UG          642   1500      em0
                    ::1                               link#5                        UH            0  16384      lo0
                    2a02:8084:6981:7880::/64          link#1                        U             6   1500      em0
                    2a02:8084:6981:7880:2e0::/80      link#1                        U             0   1500      em0
                    2a02:8084:6981:7880:2e0:67ff:fe09:9b10 link#1                   UHS           0  16384      lo0
                    2a02:8084:6981:7880:2e1::/80      link#2                        U             0   1500      em1
                    2a02:8084:6981:7880:2e1:67ff:fe09:9b11 link#2                   UHS           0  16384      lo0
                    fe80::2e0:67ff:fe09:9b10          fe80::2e0:67ff:fe09:9b10%em1  UGHS          0   1500      em1
                    fe80::362c:c4ff:febf:b8cb         fe80::362c:c4ff:febf:b8cb%em0 UGHS          0   1500      em0
                    fe80::%em0/64                     link#1                        U          4870   1500      em0
                    fe80::2e0:67ff:fe09:9b10%em0      link#1                        UHS         244  16384      lo0
                    fe80::%em1/64                     link#2                        U          4938   1500      em1
                    fe80::2e0:67ff:fe09:9b11%em1      link#2                        UHS         793  16384      lo0
                    fe80::%lo0/64                     link#5                        U             0  16384      lo0
                    fe80::1%lo0                       link#5                        UHS           0  16384      lo0
                    

                    My thinking was that because the static IPv6 LAN address I've used is still within the modem's DHCPv6 range it should be routable but it doesn't seem to get past the modem.

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

                      @azaclauson said in No LAN IPv6 address with Track Interface on WAN:

                      I realise the manual set up would break as soon as my ISP assigned my modem a different IPv6 address but as an exercise I tried to set up the manual routing. I failed to get a usable IPv6 address on my machine. The steps I took were:

                      Have you got your modem in bridge mode yet? If not, you're wasting your time. It is possible to route /64s out of whatever prefix you get. I have done that here.

                      Once you're in bridge mode, you can choose 1 /64 for each interface. You can then route any size prefix through one of those interfaces to another router. In this respect, it's little different than IPv4.

                      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...

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                      • A
                        azaclauson
                        last edited by

                        Have you got your modem in bridge mode yet?

                        No and I doubt I ever will. The modem is extremely minimal and unless there's some hidden back door there is no option to switch to bridge mode.

                        If not, you're wasting your time. It is possible to route /64s out of whatever prefix you get.

                        Yes I understand that. No matter what I do on pfSense the routing table on the modem will always assume it's the last hop and will never be able to reach the pfSense LAN interface.

                        This also corresponds to my observations of setting a static IP address on the LAN interface and then on a my PC connected to it. Both within the same /64 the modem's DHCP range is using.

                        With this hacked together configuration, ICMP6 packets from my PC do get routed successfully to public hosts on the Internet BUT on the return journey they only get as far as the modem which rejects them.

                        I tried my luck with my ISP but as soon as I mentioned IPv6 prefixes in the chat that was the last I ever heard of them.

                        It's been a good exercise and thanks for all your pointers!

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

                          @azaclauson said in No LAN IPv6 address with Track Interface on WAN:

                          This also corresponds to my observations of setting a static IP address on the LAN interface and then on a my PC connected to it. Both within the same /64 the modem's DHCP range is using.

                          You can't do that. With IPv6, the LAN is supposed to be a /64 only. If you split it, you will break some things.

                          Why not call your ISP and see if they can put the modem into bridge mode or provide one that will. That's what I had to do years ago, with an earlier modem. These days I can switch it into bridge mode and restore gateway mode on my own. Are you allowed to buy your own? If all else fails, you can get a /48 over a tunnel from he.net.

                          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...

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                          • A
                            azaclauson
                            last edited by

                            You can't do that. With IPv6, the LAN is supposed to be a /64 only. If you split it, you will break some things.

                            That's what I'd read as well but a few posts above you mentioned it was possible to further subnet /64 with manually configured routing.

                            it still seems like it's not possible to have pfSense further subnet a /64 address on the WAN such that clients on the LAN interface can use IPv6

                            You should be able to, but you can't use DHCPv6-PD to provide it. You have to manually configure routing to do it.

                            The pfSense documentation also has an IPv6 Subnet Table which has prefix lengths > 64 bits.

                            Chasing my ISP will be fruitless. They are essentially a cable TV company who do everything they can to avoid support. I did take a look at the tunnel option and it should work but my goal was to have a seamless IPv6 experience. No extra dyndns etc.

                            I actually had another idea. The only reason I have separate WAN and LAN networks is for a firewall. If I switch to an Internal/External Bridge I should be able to use my modem's IPv6 DHCP server (which works well) and still keep my firewall.

                            JKnottJ 1 Reply Last reply Reply Quote 0
                            • Bob.DigB
                              Bob.Dig LAYER 8
                              last edited by Bob.Dig

                              https://www.boards.ie/ttfpost/108440018

                              Virgin Hub 3 has modem mode which is same as thing as bridge mode
                              Modem only
                              
                              
                              To have modem mode as an option you must be on a IPv4 address
                              If you don't see modem mode listed your hub is using a Dslite IPv6 address
                              
                              You won't see modem mode when you are on a Dslite IPv6 address
                              
                              You can request virgin media to put your Hub on a IPv4 address to have access to modem mode
                              
                              Modem Mode you connect a Cat 5e or Cat 6 ethernet cable from a lan port on the hub to wan port on a different router
                              
                              All routing and wifi will be controlled by your own router 
                              
                              1 Reply Last reply Reply Quote 0
                              • A
                                azaclauson
                                last edited by

                                @Bob-Dig thx. Any idea if getting Virgin to switch the modem back to IPv4 removes IPv6? It's IPv6 connectivity that I'd like to have working.

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

                                  @azaclauson

                                  You can have other sizes for routing etc., but LANs require a /64. SLAAC depends on it.

                                  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...

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                                  • JKnottJ
                                    JKnott @azaclauson
                                    last edited by

                                    @azaclauson
                                    Having the modem in bridge mode allows pfSense to work with what's behind it. To use IPv6, the ISP normally uses DHCPv6-PD, which provides the prefix that pfSense assigns to the LANs. You may also have an IPv6 WAN address, which has absolutely nothing to do with the LAN prefixes, or routing for that matter.

                                    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...

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                                    • A
                                      azaclauson
                                      last edited by

                                      To use IPv6, the ISP normally uses DHCPv6-PD

                                      Yes but as best I can tell that's my exact problem. My ISP is not providing Prefix Delegation. Instead a single /64 network is available on the modem.

                                      I have been relatively successful switching pfSense from operating as a router between the WAN and LAN interfaces to instead operating as a transparent bridge. I've now got usable DHCP IPv6 addresses on my Windows and Linux machines and I can set firewall rules. I think there's still something missing with Router Advertisements but I can play around with that further. For the moment I know have a local firewalled IPv6 network.

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

                                        @azaclauson said in No LAN IPv6 address with Track Interface on WAN:

                                        Yes but as best I can tell that's my exact problem. My ISP is not providing Prefix Delegation. Instead a single /64 network is available on the modem.

                                        How can you tell that, when you're not set up to use prefix delegation? You will not see it coming from a modem in gateway mode, ever. You will see it only in bridge mode. All you'll see in gateway mode is router advertisements containing the prefix for the connected LAN.

                                        I posted a full DHCPv6 sequence earlier, which shows the PD part. Do you see anything like that coming from your modem? If not, you don't have it. If you want to have more than 1 /64, you must use bridge mode. There is no way around 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...

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                                        • J
                                          Jim Coogan
                                          last edited by

                                          Hi very new to IPv6 but I am in exact same scenario. Modem is in gateway mode and cannot but put into bridge.

                                          Modem's IPv6 is /64 and plugged into WAN on pfsense and pfsense gets an IPv6 ip on WAN.

                                          What I am a little confused about is what DHCPv6 Relay is for? Was thinking I could relay the DHCPv6 IPs my modem is handing out to my LAN but apparently not as I'm not seeing that suggested. I'm guessing if the LAN did pick up these relayed addresses that would be a routing problem I'm not quite grasping?

                                          Thanks

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

                                            @Jim-Coogan

                                            As on IPv4, the relay simply means your DHCP server is elsewhere, instead of on the local network. It forwards the DHCP requests to that remote 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...

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