Hi,
since a few weeks, my LAN clients occasionally lose their IPv6 connection to internet targets.
OPNSense still can still ping and traceroute, but clients cannot
Internal IPv6 connectivity between clients is still fine. Router Advertisements are working.
root@OPNsense:~ # ifconfig
igc0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
description: MODEM (opt2)
options=4e427bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
igc1: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 9000
options=4e427bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
hwaddr 20:7c:14:xx:xx:xx
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
igc2: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
description: GUEST (opt3)
options=4e427bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
inet 192.168.200.1 netmask 0xffffff00 broadcast 192.168.200.255
inet6 2003:a:xxxx:xxxx::1 prefixlen 64
inet6 fe80::227c:xxxx:xxxx:xxxx%igc2 prefixlen 64 scopeid 0x3
inet6 fda7::1 prefixlen 64
media: Ethernet autoselect
status: no carrier
nd6 options=121<PERFORMNUD,AUTO_LINKLOCAL,NO_DAD>
igc3: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=4e427bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
media: Ethernet autoselect
status: no carrier
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
igc4: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=4e427bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
media: Ethernet autoselect
status: no carrier
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
ix0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 9000
options=4e427bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
media: Ethernet autoselect (10Gbase-Twinax <full-duplex,rxpause,txpause>)
status: active
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
ix1: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=4e53fbb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_UCAST,WOL_MCAST,WOL_MAGIC,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
media: Ethernet autoselect
status: no carrier
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
ix2: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=4e53fbb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_UCAST,WOL_MCAST,WOL_MAGIC,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
media: Ethernet autoselect
status: no carrier
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
ix3: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
options=4e53fbb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_UCAST,WOL_MCAST,WOL_MAGIC,VLAN_HWFILTER,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
media: Ethernet autoselect
status: no carrier
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
lo0: flags=1008049<UP,LOOPBACK,RUNNING,MULTICAST,LOWER_UP> metric 0 mtu 16384
options=680003<RXCSUM,TXCSUM,LINKSTATE,RXCSUM_IPV6,TXCSUM_IPV6>
inet 127.0.0.1 netmask 0xff000000
inet6 ::1 prefixlen 128
inet6 fe80::1%lo0 prefixlen 64 scopeid 0xa
groups: lo
nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
enc0: flags=0 metric 0 mtu 1536
options=0
groups: enc
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
pfsync0: flags=0 metric 0 mtu 1500
options=0
maxupd: 128 defer: off version: 1400
syncok: 1
groups: pfsync
pflog0: flags=20100<PROMISC,PPROMISC> metric 0 mtu 33152
options=0
groups: pflog
lagg0: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 9000
description: LAN (lan)
options=4e427bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,LRO,WOL_MAGIC,VLAN_HWTSO,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
ether 20:7c:14:xx:xx:xx
hwaddr 00:00:00:00:00:00
inet 192.168.100.1 netmask 0xffffff00 broadcast 192.168.100.255
inet6 2003:a:xxxx:xxxx::1 prefixlen 64
inet6 fe80::227c:14ff:xxxx:xxxx%lagg0 prefixlen 64 scopeid 0xe
inet6 fda6::1 prefixlen 64
laggproto failover lagghash l2,l3,l4
laggport: igc1 flags=0<>
laggport: ix0 flags=5<MASTER,ACTIVE>
groups: lagg
media: Ethernet autoselect
status: active
nd6 options=121<PERFORMNUD,AUTO_LINKLOCAL,NO_DAD>
vlan01: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
options=4600703<RXCSUM,TXCSUM,TSO4,TSO6,LRO,RXCSUM_IPV6,TXCSUM_IPV6,MEXTPG>
ether 20:7c:14:xx:xx:xx
groups: vlan
vlan: 7 vlanproto: 802.1q vlanpcp: 0 parent interface: igc0
media: Ethernet autoselect (1000baseT <full-duplex>)
status: active
nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
pppoe0: flags=10088d1<UP,POINTOPOINT,RUNNING,NOARP,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1492
description: WAN_Telekom (opt1)
options=0
inet 87.xx.xx.xx --> 62.xx.xx.xx netmask 0xffffffff
inet6 fe80::227c:14ff:xxxx:xxxx%pppoe0 prefixlen 64 scopeid 0x10
inet6 fe80::227c:14ff:xxxx:xxxx%pppoe0 prefixlen 64 scopeid 0x10
inet6 2003:a:37f:a71a:227c:xxxx:xxxx:xxxx prefixlen 64 autoconf pltime 1800 vltime 14400
nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>
root@OPNsense:~ # cat /var/log/system/latest.log | grep -Ei 'lagg|ndp|icmp6|gateway|route|pf'
<13>1 2025-05-27T04:46:01+02:00 OPNsense.home.arpa opnsense 34605 - [meta sequenceId="234"] /usr/local/etc/rc.newwanip: ROUTING: treating '62.156.xx.xx' as far gateway for '87.xx.xx.xx/32'
<13>1 2025-05-27T04:46:01+02:00 OPNsense.home.arpa opnsense 34605 - [meta sequenceId="235"] /usr/local/etc/rc.newwanip: ROUTING: configuring inet default gateway on opt1
<13>1 2025-05-27T04:46:01+02:00 OPNsense.home.arpa opnsense 34605 - [meta sequenceId="236"] /usr/local/etc/rc.newwanip: ROUTING: setting inet default route to 62.156.xx.xx
<13>1 2025-05-27T04:46:05+02:00 OPNsense.home.arpa opnsense 43095 - [meta sequenceId="241"] /usr/local/etc/rc.newwanipv6: ROUTING: configuring inet6 default gateway on opt1
<13>1 2025-05-27T04:46:05+02:00 OPNsense.home.arpa opnsense 43095 - [meta sequenceId="242"] /usr/local/etc/rc.newwanipv6: ROUTING: keeping inet6 default route to fe80::200:ff:fe00:0%pppoe0
<13>1 2025-05-27T04:46:07+02:00 OPNsense.home.arpa opnsense 34605 - [meta sequenceId="245"] /usr/local/etc/rc.newwanip: IP gateway change detected, killing states for 62.156.xx.xx
<13>1 2025-05-27T10:08:32+02:00 OPNsense.home.arpa kernel - - [meta sequenceId="3"] <6>lagg0: promiscuous mode enabled
<13>1 2025-05-27T10:08:35+02:00 OPNsense.home.arpa kernel - - [meta sequenceId="6"] <6>lagg0: promiscuous mode disabled
<13>1 2025-05-27T10:14:35+02:00 OPNsense.home.arpa kernel - - [meta sequenceId="3"] <6>lagg0: promiscuous mode enabled
<13>1 2025-05-27T10:14:48+02:00 OPNsense.home.arpa kernel - - [meta sequenceId="6"] <6>lagg0: promiscuous mode disabled
Only a reboot of the router fixes the issue. For either a few hours, a few days... until all clients are offline with IPv6 again.
I am on a Deutsche Telekom VDSL Line using a Zyxel Modem.
Can someone here help me find the root cause?