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    HA CARP - IPv6 Two masters

    Scheduled Pinned Locked Moved HA/CARP/VIPs
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    • A Offline
      anthonysomerset
      last edited by

      Just want to add i appear to have hit this "bug" in one of our SG-4860 clusters

      our IPv6 addresses are in their shortened form with no leading zeros, had to reboot secondary to clear this out, will keep an eye on things

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      • X Offline
        xciter327
        last edited by

        I am also hitting something similar this in our office/test system.

        Both devices are connected to a Cisco 3560G switch. IGMP snooping and ipv6 mld snooping are disabled. All ports are set to "portfast". There are no "loops" in the network. There are no topology changes.

        You will notice that each one sees the others advertisements and their own.

        Primary:
        16:42:40.428976 IP6 fe80::ec4:7aff:feab:3724 > ff02::12: ip-proto-112 36
        16:42:42.597228 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36
        16:42:50.886692 IP6 fe80::ec4:7aff:feab:3724 > ff02::12: ip-proto-112 36
        16:42:52.607533 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36
        16:43:01.382988 IP6 fe80::ec4:7aff:feab:3724 > ff02::12: ip-proto-112 36
        16:43:02.612549 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36

        Backup:
        16:42:09.212760 IP6 fe80::ec4:7aff:feab:3724 > ff02::12: ip-proto-112 36
        16:42:12.573960 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36
        16:42:19.608720 IP6 fe80::ec4:7aff:feab:3724 > ff02::12: ip-proto-112 36
        16:42:22.578900 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36
        16:42:30.015028 IP6 fe80::ec4:7aff:feab:3724 > ff02::12: ip-proto-112 36
        16:42:32.585911 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36

        This only happens for IPv6 CARP IPs.

        Here are the interfaces, just to confirm the vhid:

        Primary:
        igb0: flags=8943 <up,broadcast,running,promisc,simplex,multicast>metric 0 mtu 1500
        options=6400bb <rxcsum,txcsum,vlan_mtu,vlan_hwtagging,jumbo_mtu,vlan_hwcsum,vlan_hwtso,rxcsum_ipv6,txcsum_ipv6>ether 0c:c4:7a:ac:82:1a
        hwaddr 0c:c4:7a:ac:82:1a
        inet6 fe80::ec4:7aff:feac:821a%igb0 prefixlen 64 scopeid 0x1
        inet6 xxxx:xxxx:1:2::3 prefixlen 124
        inet6 xxxx:xxxx:1:2::2 prefixlen 124 vhid 4
        inet yyy.yyy.233.108 netmask 0xfffffff0 broadcast yyy.yyy.233.111
        inet yyy.yyy.233.110 netmask 0xfffffff0 broadcast yyy.yyy.233.111 vhid 1
        nd6 options=21 <performnud,auto_linklocal>media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
        carp: MASTER vhid 1 advbase 10 advskew 1
        carp: MASTER vhid 4 advbase 10 advskew 1

        Backup:
        igb0: flags=8943 <up,broadcast,running,promisc,simplex,multicast>metric 0 mtu 1500
        options=6400bb <rxcsum,txcsum,vlan_mtu,vlan_hwtagging,jumbo_mtu,vlan_hwcsum,vlan_hwtso,rxcsum_ipv6,txcsum_ipv6>ether 0c:c4:7a🆎37:24
        hwaddr 0c:c4:7a🆎37:24
        inet6 fe80::ec4:7aff:feab:3724%igb0 prefixlen 64 scopeid 0x1
        inet6 xxxx:xxxx:1:2::4 prefixlen 124
        inet yyy.yyy.233.109 netmask 0xfffffff0 broadcast yyy.yyy.233.111
        inet yyy.yyy.233.110 netmask 0xfffffff0 broadcast yyy.yyy.233.111 vhid 1
        nd6 options=21 <performnud,auto_linklocal>media: Ethernet autoselect (1000baseT <full-duplex>)
        status: active
        carp: MASTER vhid 4 advbase 10 advskew 101
        carp: BACKUP vhid 1 advbase 10 advskew 101

        So the CARP interface is correctly assigned to the primary node, but the backup one still claims its master in the dashboard and with "ifconfig igb0".</full-duplex></performnud,auto_linklocal></rxcsum,txcsum,vlan_mtu,vlan_hwtagging,jumbo_mtu,vlan_hwcsum,vlan_hwtso,rxcsum_ipv6,txcsum_ipv6></up,broadcast,running,promisc,simplex,multicast></full-duplex></performnud,auto_linklocal></rxcsum,txcsum,vlan_mtu,vlan_hwtagging,jumbo_mtu,vlan_hwcsum,vlan_hwtso,rxcsum_ipv6,txcsum_ipv6></up,broadcast,running,promisc,simplex,multicast>

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        • DerelictD Offline
          Derelict LAYER 8 Netgate
          last edited by Derelict

          Why did you play with advbase/advskew?

          Use 1/0 on the primary that will sync 1/100 to the secondary. Then just leave it alone.

          Chattanooga, Tennessee, USA
          A comprehensive network diagram is worth 10,000 words and 15 conference calls.
          DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
          Do Not Chat For Help! NO_WAN_EGRESS(TM)

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          • X Offline
            xciter327
            last edited by

            Yes. I did try multiple base values between 0 - 20 for the base and 0 and 1 for skew. The settings are correctly(+100 for skew) transferred to the backup unit. Still backup thinks it's primary for IPv6.

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            • DerelictD Offline
              Derelict LAYER 8 Netgate
              last edited by Derelict

              Are you 100% certain the case described in reply #15 ^ is not present?

              Use 1/0 on the primary that will sync 1/100 to the secondary. Then just leave it alone.

              Just do that. If changing it didn't correct it it is not the problem.

              Packet capture on both nodes and see if you see the CARP going out the interface or in the interface. You can filter on CARP only in Diagnostics > Packet Capture.

              Chattanooga, Tennessee, USA
              A comprehensive network diagram is worth 10,000 words and 15 conference calls.
              DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
              Do Not Chat For Help! NO_WAN_EGRESS(TM)

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              • X Offline
                xciter327
                last edited by

                1. Regarding post #15 solution. I tried both shorthand(no leading zeroes) and full notation with nothing omitted.
                2. I included a tcpdump in my first post. It looks to me that they are both receiving each other's updates.

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                • I Offline
                  IcePick
                  last edited by

                  Have you tried changing to addresses that CAN NOT be shortened to have a :: ?

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                  • X Offline
                    xciter327
                    last edited by

                    @IcePick:

                    Have you tried changing to addresses that CAN NOT be shortened to have a :: ?

                    Yes I did. No difference.

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                    • DerelictD Offline
                      Derelict LAYER 8 Netgate
                      last edited by

                      Did you put base/skew back to the default or not?

                      Chattanooga, Tennessee, USA
                      A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                      DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                      Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                      • X Offline
                        xciter327
                        last edited by

                        @Derelict:

                        Did you put base/skew back to the default or not?

                        Yes, I did.

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                        • DerelictD Offline
                          Derelict LAYER 8 Netgate
                          last edited by

                          Well, cut loose with more. Screen shots, pcaps, whatever. IPv6 CARP works.

                          Chattanooga, Tennessee, USA
                          A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                          DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                          Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                          • X Offline
                            xciter327
                            last edited by

                            I disabled "DHCP Snooping" on the directly connected switch. That was somehow blocking stuff. Seems to be working OK now. I can no longer reproduce the issue. Will post if I can.

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                            • DerelictD Offline
                              Derelict LAYER 8 Netgate
                              last edited by

                              Amazing. It was a setting on the switch. Simply amazing.

                              Glad you found it.

                              Chattanooga, Tennessee, USA
                              A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                              DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                              Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                              • X Offline
                                xciter327
                                last edited by

                                So the problem is kind of back.

                                Same situation. Secondary pfsense become master for both IPv6 CARP groups, both report as master. The weird thing now is that if I shut down the secondary pfsense box IPv6 stops working completely. The primary box reports CARP status "Master"(as it always does), but the address is not reachable on the local LAN.

                                IGMP / DHCP snooping is disabled on the two switches between test PC and firewalls. The IPv4 CARP works fine.

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                                • DerelictD Offline
                                  Derelict LAYER 8 Netgate
                                  last edited by

                                  Again, it sounds like something at layer 2.

                                  Either of the nodes will show MASTER if it does not receive the heartbeats from the other node. Solving dual MASTER is generally as simple as fixing the reason(s) that one node is not seeing the heartbeats from the other node.

                                  Chattanooga, Tennessee, USA
                                  A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                                  DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                                  Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                                  • X Offline
                                    xciter327
                                    last edited by xciter327

                                    It most definitely not L2 issue. The devices can see each other. Confirmed with tcpdump.( tcpdump -i igb0 -ttt -n proto CARP). There are 2 VHIDs on this interface.

                                    Master:
                                    00:00:00.000094 IP 217.117.yyy.xxx > 224.0.0.18: VRRPv2, Advertisement, vrid 1, prio 1, authtype none, intvl 1s, length 36
                                    00:00:01.004961 IP 217.117.yyy.xxx > 224.0.0.18: VRRPv2, Advertisement, vrid 1, prio 1, authtype none, intvl 1s, length 36
                                    00:00:00.000103 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36
                                    00:00:01.005069 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36

                                    Backup:
                                    00:00:00.000064 IP 217.117.yyy.xxx > 224.0.0.18: VRRPv2, Advertisement, vrid 1, prio 1, authtype none, intvl 1s, length 36
                                    00:00:01.004781 IP 217.117.yyy.xxx > 224.0.0.18: VRRPv2, Advertisement, vrid 1, prio 1, authtype none, intvl 1s, length 36
                                    00:00:00.000062 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36
                                    00:00:01.004907 IP6 fe80::ec4:7aff:feac:821a > ff02::12: ip-proto-112 36

                                    What I did is to download a config backup from each unit and a do a restore from config. That fixed the issue for me. There were no changes made to the underlying switching network.

                                    I also hit this bug with 2.4.3-Release-P1. That left me with one extra VHID on each interface stuck in "INIT" state. Rebooting the firewall is the only way I found to fix it.

                                    P.S. - Yesterday I also tried shutting down the "Backup" unit and fully un-plugging it from the network. While the IPv6 CARP interface on the LAN was showing as "up" and "master" on the only firewall left, IPv6 connectivity was not working until I rebooted the firewall.

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                                    • X Offline
                                      xciter327
                                      last edited by

                                      This post is deleted!
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                                      • X Offline
                                        xciter327
                                        last edited by xciter327

                                        Happens on other interfaces too(igb2.12):

                                        Master:
                                        00:00:00.000000 IP 172.28.0.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 6, prio 1, authtype none, intvl 1s, length 36
                                        00:00:01.009252 IP 172.28.0.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 6, prio 1, authtype none, intvl 1s, length 36

                                        Backup:
                                        00:00:00.000000 IP 172.28.0.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 6, prio 1, authtype none, intvl 1s, length 36
                                        00:00:01.010086 IP 172.28.0.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 6, prio 1, authtype none, intvl 1s, length 36

                                        Interface shows "Master" on both devices.

                                        igb1:
                                        Master:
                                        00:00:00.431700 IP 172.29.100.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 2, prio 1, authtype none, intvl 1s, length 36
                                        00:00:00.000072 IP6 fe80::ec4:7aff:feac:821b > ff02::12: ip-proto-112 36
                                        00:00:00.964265 IP6 fe80::ec4:7aff:feab:3725 > ff02::12: ip-proto-112 36
                                        00:00:00.040245 IP6 fe80::ec4:7aff:feac:821b > ff02::12: ip-proto-112 36
                                        00:00:00.000067 IP 172.29.100.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 2, prio 1, authtype none, intvl 1s, length 36

                                        Backup:
                                        00:00:01.004330 IP 172.29.100.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 2, prio 1, authtype none, intvl 1s, length 36
                                        00:00:00.000053 IP6 fe80::ec4:7aff:feac:821b > ff02::12: ip-proto-112 36
                                        00:00:00.185346 IP6 fe80::ec4:7aff:feab:3725 > ff02::12: ip-proto-112 36
                                        00:00:00.819555 IP6 fe80::ec4:7aff:feac:821b > ff02::12: ip-proto-112 36
                                        00:00:00.000135 IP 172.29.100.1 > 224.0.0.18: VRRPv2, Advertisement, vrid 2, prio 1, authtype none, intvl 1s, length 36

                                        For some reason the "Backup" unit is also receiving it's own advertisements, but only on IPv6.

                                        Seems setting "advskew" to 100 on primary one, waiting for backup unit to get the config and rebooting the backup unit fixes the issue with the advertisements. Pending further testing of course.

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                                        • DerelictD Offline
                                          Derelict LAYER 8 Netgate
                                          last edited by

                                          You should be decoding those as CARP, not VRRP so we can see what is going on in a more clear fashion. You can:

                                          • Set the protocol to CARP then view the capture in Diagnostics > Packet Capture. That will result in tcpdump decoding as CARP.

                                          • Set wireshark to decode as CARP by right-clicking a VRRP packet and using Decode As to decode protocol 112 as CARP instead of VRRP.

                                          0_1530203621154_Screen Shot 2018-06-28 at 9.33.07 AM.png

                                          You should never have to touch advbase/advskew. They should be 1/0 on the primary which should sync to 1/100 on the secondary.

                                          I do recall one issue with IPv6 CARP and the way the VIPs are defined. I cannot remember if it was leading zeroes, capital hex digits or what. How are you specifying your CARP VIPs?

                                          For some reason the “Backup” unit is also receiving it’s own advertisements, but only on IPv6.

                                          If they both think they are MASTER on a VIP they will both be advertising. If you look at the MAC addresses in the capture, you will likely see that the secondary is not receiving its own advertisements, but that it is sending them along with the primary.

                                          Chattanooga, Tennessee, USA
                                          A comprehensive network diagram is worth 10,000 words and 15 conference calls.
                                          DO NOT set a source address/port in a port forward or firewall rule unless you KNOW you need it!
                                          Do Not Chat For Help! NO_WAN_EGRESS(TM)

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                                          • X Offline
                                            xciter327
                                            last edited by xciter327

                                            Yes, I agree. I saw a suggestion about that. Need to add "-T carp" to the tcpdump command for it work:

                                            tcpdump -npi igb1 -T carp -e | egrep "224.0.0.18|ff02::12:"

                                            for example. The "egrep" is there because if I just use "expression" carp, it does not dump the IPv6 traffic.

                                            Back to my problem. I've reverted to 1/0(and via config sync 1/100 on backup).

                                            How I am able to reproduce the problem:

                                            • Make a change on any CARP VIP
                                            • Reboot primary

                                            However if I reboot the backup unit after I've made a change on CARP, everything works as advertised. Going to do some more dumping to try to figure it out.

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