Hello, recently after enabling ipv6_privacy in /etc/rc.conf and rebooting, I've
been unable to get IPv6 connectivity to work in a hosted environment. (I don't
know if this is a red herring or not.) I've tried disabling it, and even after
rebooting, it still doesn't work. (Doesn't work meaning: I'm unable to ping6
hosts on the Internet that are reachable, e.g. ipv6.google.com.) I confirmed
ipv6_privacy is actually disabled:
# sysctl -a | grep tempaddr
net.inet6.ip6.use_tempaddr: 0
net.inet6.ip6.prefer_tempaddr: 0
If I boot into a Linux environment (the provider has a Rescue mode), I'm able
to reach IPv6 just fine. Furthermore, if I then reboot back into FreeBSD
13.0-RELEASE-p10 it will work for around ~5 minutes and then connections time
out.
Given the behavior and based on some tcpdumps, it looks like my system is not
responding to the upstream router's Neighbor Solicitation messages. If I boot
into Linux, it respond to the NS messages, the router caches the MAC address,
and IPv6 works. If I'm fast enough and reboot into FreeBSD, IPv6 works until
the the entry expires, and then I just see this:
13:24:58.901780 IP6 2600:3c00::f03c:91ff:feb0:a56f >
2605:6400:10:968:22:da15:28a6:c800: ICMP6, echo request, seq 40, length 16
13:24:59.277713 IP6 2600:3c00::8678:acff:fe1c:ec41 > ff02::1:ffb0:a56f: ICMP6,
neighbor solicitation, who has 2600:3c00::f03c:91ff:feb0:a56f, length 32
13:24:59.277799 IP6 2600:3c00::8678:acff:fe1c:ec41 > ff02::1:ffb0:a56f: ICMP6,
neighbor solicitation, who has 2600:3c00::f03c:91ff:feb0:a56f, length 32
3 packets, the echo request, then two NS requests, and no response -- and then
it just repeats.
I confirmed b0:a5:6f is the Device ID part of my MAC:
# ifconfig em0
em0: flags=8863<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=481209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,VLAN_HWFILTER,NOMAP>
ether f2:3c:91:b0:a5:6f <---
inet6 fe80::f03c:91ff:feb0:a56f%em0 prefixlen 64 scopeid 0x1
inet6 2600:3c00::f03c:91ff:feb0:a56f prefixlen 64 autoconf
inet6 2600:3c00:e000:137::1 prefixlen 128
inet6 2600:3c00:e000:137::1:1 prefixlen 128
inet6 2600:3c00:e000:137::2:1 prefixlen 128
inet6 2600:3c00:e000:137::3:1 prefixlen 128
inet6 2600:3c00:e000:137:cafe:8a2e:370:7334 prefixlen 128
inet 96.126.127.161 netmask 0xffffff00 broadcast 96.126.127.255
inet 173.255.203.45 netmask 0xffffffff broadcast 173.255.203.45
inet 96.126.122.129 netmask 0xffffffff broadcast 96.126.122.129
inet 50.116.26.213 netmask 0xffffffff broadcast 50.116.26.213
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
nd6 options=8023<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL,DEFAULTIF>
Therefore the Solicited-node multicast address ff02::1:ffb0:a56f looks to be
correct. I've also confirmed the router's address is within the assigned SLAAC
network (Router: 2600:3c00::8678:acff:fe1c:ec41, SLAAC address:
2600:3c00::f03c:91ff:feb0:a56f/64).Furthermore, the multicast address does show
up in `ifmcstat`:
# ifmcstat
em0:
inet6 fe80::f03c:91ff:feb0:a56f%em0 scopeid 0x1
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff02::1:ff70:7334%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:70:73:34
group ff02::1:ff03:1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:03:00:01
group ff02::1:ff02:1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:02:00:01
group ff02::1:ff01:1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:01:00:01
group ff02::1:ff00:1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:00:00:01
inet 96.126.127.161
igmpv3 rv 2 qi 125 qri 10 uri 3
group 224.0.0.1 mode exclude
mcast-macaddr 01:00:5e:00:00:01
inet6 fe80::f03c:91ff:feb0:a56f%em0 scopeid 0x1
mldv2 flags=2<USEALLOW> rv 2 qi 125 qri 10 uri 3
group ff01::1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::2:bdc6:c84d%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:bd:c6:c8:4d
group ff02::2:ffbd:c6c8%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:ff:bd:c6:c8
group ff02::1%em0 scopeid 0x1 mode exclude
mcast-macaddr 33:33:00:00:00:01
group ff02::1:ffb0:a56f%em0 scopeid 0x1 mode exclude <---
mcast-macaddr 33:33:ff:b0:a5:6f
I can even ping the address and it replies!
# ping6 ff02::1:ffb0:a56f
PING6(56=40+8+8 bytes) fe80::f03c:91ff:feb0:a56f%em0 --> ff02::1:ffb0:a56f
16 bytes from fe80::f03c:91ff:feb0:a56f%em0, icmp_seq=0 hlim=64 time=0.451 ms
16 bytes from fe80::f03c:91ff:feb0:a56f%em0, icmp_seq=1 hlim=64 time=0.446 ms
16 bytes from fe80::f03c:91ff:feb0:a56f%em0, icmp_seq=2 hlim=64 time=0.618 ms
^C
Does anyone have any thoughts why it's not responding to the Neighbor
Solicitation messages? I've been troubleshooting this for a few days now and
can't figure it out. I also tried booting kernel.old (which I think is -p8 or
-p9), but it made no difference. I've tried with and without pf enabled --
again, no difference.
I don't know if this is useful, but I validated routes are being discovered:
# ndp -na
Neighbor Linklayer Address Netif Expire S
Flags
2600:3c00:e000:137::1:1 f2:3c:91:b0:a5:6f em0 permanent R
2600:3c00:e000:137::1 f2:3c:91:b0:a5:6f em0 permanent R
fe80::1%em0 00:05:73:a0:0f:ff em0 23h56m36s S R
<---
2600:3c00:e000:137::3:1 f2:3c:91:b0:a5:6f em0 permanent R
2600:3c00:e000:137::2:1 f2:3c:91:b0:a5:6f em0 permanent R
2600:3c00::f03c:91ff:feb0:a56f f2:3c:91:b0:a5:6f em0 permanent R
fe80::f03c:91ff:feb0:a56f%em0 f2:3c:91:b0:a5:6f em0 permanent R
fe80::8678:acff:fe1c:ec41%em0 84:78:ac:1c:ec:41 em0 23h49m7s S R
<---
2600:3c00:e000:137:cafe:8a2e:370:7334 f2:3c:91:b0:a5:6f em0 permanent R
# netstat -nr6
Routing tables
Internet6:
Destination Gateway Flags
Netif Expire
::/96 ::1 UGRS
lo0
default fe80::1%em0 UG
em0 <---
::1 link#2 UHS
lo0
::ffff:0.0.0.0/96 ::1 UGRS
lo0
2600:3c00::f03c:91ff:feb0:a56f link#1 UHS
lo0
2600:3c00:e000:137::1 link#1 UHS
lo0
2600:3c00:e000:137::1:1 link#1 UHS
lo0
2600:3c00:e000:137::2:1 link#1 UHS
lo0
2600:3c00:e000:137::3:1 link#1 UHS
lo0
2600:3c00:e000:137:cafe:8a2e:370:7334 link#1 UHS
lo0
fe80::/10 ::1 UGRS
lo0
fe80::%em0/64 link#1 U
em0
fe80::f03c:91ff:feb0:a56f%em0 link#1 UHS
lo0
fe80::%lo0/64 link#2 U
lo0
fe80::1%lo0 link#2 UHS
lo0
ff02::/16 ::1 UGRS
lo0
And here's the IPv6 part in my rc.conf:
# ipv6
rtsold_enable="YES"
rtsold_flags="-aF"
#ipv6_activate_all_interfaces="YES"
ipv6_network_interfaces="em0"
ipv6_default_interface="em0"
ifconfig_em0_ipv6="inet6 accept_rtadv"
ifconfig_em0_aliases="\
inet6 2600:3c00:e000:0137::0:1/128 \
inet6 2600:3c00:e000:0137::1:1/128 \
inet6 2600:3c00:e000:0137::2:1/128 \
inet6 2600:3c00:e000:0137::3:1/128 \
inet6 2600:3c00:e000:0137:cafe:8a2e:0370:7334/128"
I'm at a complete loss. Any help troubleshooting this would be greatly
appreciated.
Sincerely,
--wcarson
