IPv6 Broken in 12

[Hans Petter Selasky]

On 1/4/19 3:29 PM, Shamim Shahriar wrote:
> Dear List members, good afternoon and happy new year
> 
> I am trying to setup a FreeBSD server v12 amd64, and it appears that IPv6
> on that is actually broken. I have confirmed that by having same hardware
> running v11.2 (amd64), and that is working without any issue.
> 
> Preamble:
> The "infrastructure" in question is running mostly Juniper devices, and the
> routers are advertising everything. So the only thing (related to IPv6) I
> have in my rc.conf are
> 
> ifconfig_em0_ipv6="inet6 accept_rtadv"
> rtsold_enable="YES"
> 
> This gives the machines an IPv6 from the intended subnet, and also
> configures the defaultroute for the devices
> 
> em0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
> 
> options=81209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,VLAN_HWFILTER>
>          ether 52:54:00:1a:a4:1a
>          inet6 fe80::e:f:11:12:a41a%em0 prefixlen 64 scopeid 0x1
>          inet6 a:b:c:d:e:f:11:12:a41a prefixlen 64 autoconf
>          inet 172.16.1.23 netmask 0xffffff00 broadcast 172.16.1.255
>          media: Ethernet autoselect (1000baseT <full-duplex>)
>          status: active
>          nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
> 
> 
> # netstat -nr
> Routing tables
> 
> Internet:
> Destination        Gateway            Flags     Netif Expire
> default            172.16.1.1       UGS         em0
> 127.0.0.1          link#2             UH          lo0
> 172.16.1.0/24    link#1             U           em0
> 172.16.1.23      link#1             UHS         lo0
> 
> Internet6:
> Destination                       Gateway                       Flags
> Netif Expire
> ::/96                             ::1                           UGRS
> lo0
> default                           fe80::e:f:11:12:200%em0       UG
> em0
> ::1                               link#2                        UH
> lo0
> ::ffff:0.0.0.0/96                 ::1                           UGRS
> lo0
> a:b:c:d::/64                      link#1                        U
> em0
> a:b:c:d:e:f:11:12:a41a            link#1                        UHS
> lo0
> fe80::/10                         ::1                           UGRS
> lo0
> fe80::%em0/64                     link#1                        U
> em0
> fe80::e:f:11:12:a41a%em0          link#1                        UHS
> lo0
> fe80::%lo0/64                     link#2                        U
> lo0
> fe80::1%lo0                       link#2                        UHS
> lo0
> ff02::/16
> 
> 
> Problem:
> In FreeBSD v12, if I do a tcpdump, it appears that the router is constantly
> asking who has my IP, and the machine is not responding to it at all.
> 
> (running on two different console on the same machine)
> ping6 mx1
> PING6(56=40+8+8 bytes) a:b:c:d:5054:ff:fe1a:a41a --> 2222:aa:bb:cc::72
> 
> 
> # tcpdump -ni em0 icmp6
> 14:17:18.980755 IP6 a:b:c:d:e:f:11:12:a41a > 2222:aa:bb:cc::72: ICMP6, echo
> request, seq 0, length 16
> 14:17:19.617708 IP6 fe80::200:5eff:fe00:200 > ff02::1:ff1a:a41a: ICMP6,
> neighbor solicitation, who has a:b:c:d:e:f:11:12:a41a, length 32
> 14:17:20.003172 IP6 a:b:c:d:e:f:11:12:a41a > 2222:aa:bb:cc::72: ICMP6, echo
> request, seq 1, length 16
> 14:17:20.617615 IP6 fe80::200:5eff:fe00:200 > ff02::1:ff1a:a41a: ICMP6,
> neighbor solicitation, who has a:b:c:d:e:f:11:12:a41a, length 32
> 14:17:21.023423 IP6 a:b:c:d:e:f:11:12:a41a > 2222:aa:bb:cc::72: ICMP6, echo
> request, seq 2, length 16
> 
> 
> Whereas, if I am running FreeBSD v11.2, it is working alright. I am getting
> the ping response and what not.
> 
> NOTE: Both the v12 and v11.2 was downloaded as of today (in a matter of
> minutes -- not even hours) for setting up the machines.
> 
> Could someone please confirm if what I am seeing is expected? If yes, how
> soon is this likely to be fixed?
> 
> If you require further information or need me to run more tests, please do
> let me know. I will have the machines running for some time (reasonable
> time), before I decide which of the two will prevail :D
> 
> Thanks and regards

Hi,

Can you try the second debug patch mentioned here:
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=233535

Is this issue isolated to Link-Local IPv6 or is global IPv6 involved aswell?

--HPS