Hallo, gestern hat Mailcow einen Absturz des gesamten Cloudservers verursacht (Rootserver bei Hetzner, Ubuntu 18, alles auf aktuellem Stand). Nach einem kurzen Blick in die syslog war klar, dass irgendwas mit IPv6 nicht passt. Also IPv6 in der Mailkuh deaktiviert. Seitdem läuft zwar wieder alles, aber das ist ja keine Lösung!?

Hier ein paar kurze Ausschnitte aus der syslog:
Sep 27 18:56:13 AKServer kernel: [ 9.515265] Bridge firewalling registered Sep 27 18:56:13 AKServer kernel: [ 9.522557] bpfilter: Loaded bpfilter_umh pid 1085 Sep 27 18:56:13 AKServer kernel: [ 9.522808] Started bpfilter Sep 27 18:56:13 AKServer kernel: [ 9.626689] Initializing XFRM netlink socket Sep 27 18:56:13 AKServer systemd-networkd[604]: rtnl: received neighbor for link '3' we don't know about, ignoring. Sep 27 18:56:13 AKServer systemd-networkd[604]: rtnl: received neighbor for link '3' we don't know about, ignoring. Sep 27 18:56:13 AKServer dockerd[987]: time="2022-09-27T18:56:13.508448521+02:00" level=error msg="Could not add route to IPv6 network fd00:dead:beef:c0::1/80 via device docker0: network is down" Sep 27 18:56:13 AKServer systemd-networkd[604]: rtnl: received neighbor for link '3' we don't know about, ignoring. Sep 27 18:56:13 AKServer systemd-networkd[604]: rtnl: received neighbor for link '3' we don't know about, ignoring. Sep 27 18:56:13 AKServer systemd-udevd[447]: Using default interface naming scheme 'v245'. Sep 27 18:56:13 AKServer systemd-udevd[447]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable. Sep 27 18:56:13 AKServer systemd-timesyncd[591]: Network configuration changed, trying to establish connection. Sep 27 18:56:13 AKServer networkd-dispatcher[676]: WARNING:Unknown index 3 seen, reloading interface list Sep 27 18:56:13 AKServer systemd-timesyncd[591]: Network configuration changed, trying to establish connection. Sep 27 18:56:13 AKServer systemd-networkd[604]: docker0: Link UP Sep 27 18:56:13 AKServer systemd-timesyncd[591]: Network configuration changed, trying to establish connection. Sep 27 18:56:13 AKServer dockerd[987]: time="2022-09-27T18:56:13.568184428+02:00" level=error msg="Could not add route to IPv6 network fd4d:6169:6c63:6f77::1/64 via device br-mailcow: network is down" Sep 27 18:56:13 AKServer systemd-udevd[447]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable. Sep 27 18:56:13 AKServer systemd-networkd[604]: rtnl: received neighbor for link '4' we don't know about, ignoring. Sep 27 18:56:13 AKServer networkd-dispatcher[676]: WARNING:Unknown index 4 seen, reloading interface list Sep 27 18:56:13 AKServer systemd-networkd[604]: rtnl: received neighbor for link '4' we don't know about, ignoring. Sep 27 18:56:13 AKServer systemd-networkd[604]: message repeated 2 times: [ rtnl: received neighbor for link '4' we don't know about, ignoring.] Sep 27 18:56:13 AKServer systemd-timesyncd[591]: Network configuration changed, trying to establish connection. Sep 27 18:56:13 AKServer systemd-networkd[604]: br-mailcow: Link UP Sep 27 18:56:13 AKServer systemd-timesyncd[591]: Network configuration changed, trying to establish connection. Sep 27 18:56:13 AKServer dockerd[987]: time="2022-09-27T18:56:13.661325346+02:00" level=info msg="Default bridge (docker0) is assigned with an IP address 172.17.0.0/16. Daemon option --bip can be used to set a preferred IP address" Sep 27 18:56:13 AKServer systemd-udevd[445]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable. Sep 27 18:56:13 AKServer systemd-udevd[445]: vethf9f804b: Could not generate persistent MAC: No data available Sep 27 18:56:13 AKServer systemd-udevd[447]: ethtool: autonegotiation is unset or enabled, the speed and duplex are not writable. Sep 27 18:56:13 AKServer systemd-udevd[447]: vethd0ad934: Could not generate persistent MAC: No data available Sep 27 18:56:13 AKServer systemd-timesyncd[591]: Network configuration changed, trying to establish connection. Sep 27 18:56:13 AKServer kernel: [ 9.874339] br-mailcow: port 1(vethd0ad934) entered blocking state Sep 27 18:56:13 AKServer kernel: [ 9.874342] br-mailcow: port 1(vethd0ad934) entered disabled state Sep 27 18:56:13 AKServer kernel: [ 9.874453] device vethd0ad934 entered promiscuous mode Sep 27 18:56:13 AKServer kernel: [ 9.874609] br-mailcow: port 1(vethd0ad934) entered blocking state Sep 27 18:56:13 AKServer kernel: [ 9.874612] br-mailcow: port 1(vethd0ad934) entered forwarding state Sep 27 18:56:13 AKServer kernel: [ 9.874642] IPv6: ADDRCONF(NETDEV_CHANGE): br-mailcow: link becomes ready Sep 27 18:56:13 AKServer kernel: [ 9.874817] br-mailcow: port 1(vethd0ad934) entered disabled state Sep 27 18:56:13 AKServer systemd-networkd[604]: vethd0ad934: Link UP Sep 27 18:56:13 AKServer systemd-networkd[604]: br-mailcow: Gained carrier

Hat jemand eine Idee?