I can confirm the same issues with `systemd-networkd` in Xenial (and Debian Stretch). Do you know if there is a patch from a modern `systemd` that can be used to backport a fix to older versions?
When not using `systemd-networkd` (like older dists or "vanilla" Xenial) it is possible to see when an default route expires, but that data seems to be lost with `systemd-networkd`. Trusty without `systemd-networkd`: ``` $ ip -6 r [...] default via fe80::209:fff:fe09:5 dev eth0 proto kernel metric 1024 expires 1566sec ``` Xenial without `systemd-networkd`: ``` $ ip -6 r [...] default via fe80::209:fff:fe09:5 dev ens192 proto ra metric 1024 expires 1545sec pref medium ``` Xenial WITH `systemd-networkd`: ``` $ ip -6 r [...] default via fe80::209:fff:fe09:5 dev ens192 proto ra metric 1024 pref medium ``` -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1800836 Title: systemd-networkd doesn't process IPv6 RA properly Status in systemd package in Ubuntu: Confirmed Bug description: The gateways/firewalls in our DC are highly available and when there is a failover their IPv6 VIP (fe80::1) moves from the master to the backup one. We found that only our Bionic VMs behind those gateways had issues after a failover. Those Bionic VMs were all running systemd-networkd (from netplan) and before the failover they had: $ ip -6 route ... default via fe80::1 dev eth0 proto ra metric 1024 pref medium But after a failover: $ ip -6 route ... default proto ra metric 1024 nexthop via fe80::1 dev eth0 weight 1 nexthop via fe80::210:18ff:febe:6750 dev eth0 weight 1 And after another failover: $ ip -6 route ... default proto ra metric 1024 nexthop via fe80::1 dev eth0 weight 1 nexthop via fe80::210:18ff:febe:6750 dev eth0 weight 1 nexthop via fe80::210:18ff:fe77:b558 dev eth0 weight 1 This is problematic as those then use fe80::210:18ff:fe77:b558%$IFACE as their default gateway even when this gateway is unavailable: $ ip -6 route get :: :: from :: via fe80::210:18ff:fe77:b558 dev eth0 proto ra src fe80::a800:ff:fe51:8c37 metric 1024 pref medium We concluded it was a systemd-networkd bug after checking that the following combinations were NOT affected: 1) Xenial+4.4 kernel 2) Xenial+4.15 kernel 3) Bionic+ifupdown Additional information: $ apt-cache policy systemd systemd: Installed: 237-3ubuntu10.3 Candidate: 237-3ubuntu10.3 Version table: *** 237-3ubuntu10.3 500 500 http://archive.ubuntu.com/ubuntu bionic-updates/main amd64 Packages 100 /var/lib/dpkg/status 237-3ubuntu10 500 500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages $ lsb_release -rd Description: Ubuntu 18.04.1 LTS Release: 18.04 ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: systemd 237-3ubuntu10.3 ProcVersionSignature: Ubuntu 4.15.0-38.41-generic 4.15.18 Uname: Linux 4.15.0-38-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.4 Architecture: amd64 Date: Wed Oct 31 08:47:28 2018 Lspci: Error: [Errno 2] No such file or directory: 'lspci': 'lspci' Lsusb: Error: [Errno 2] No such file or directory: 'lsusb': 'lsusb' MachineType: QEMU Standard PC (i440FX + PIIX, 1996) ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=en_US.UTF-8 SHELL=/bin/bash ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-38-generic root=UUID=43b7ee2e-2ab1-4505-8e0b-d9fe0563a034 ro console=ttyS0 net.ifnames=0 vsyscall=none kaslr nmi_watchdog=0 possible_cpus=1 SourcePackage: systemd UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/01/2014 dmi.bios.vendor: SeaBIOS dmi.bios.version: Ubuntu-1.8.2-1ubuntu1 dmi.chassis.type: 1 dmi.chassis.vendor: QEMU dmi.chassis.version: pc-i440fx-xenial dmi.modalias: dmi:bvnSeaBIOS:bvrUbuntu-1.8.2-1ubuntu1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-xenial:cvnQEMU:ct1:cvrpc-i440fx-xenial: dmi.product.name: Standard PC (i440FX + PIIX, 1996) dmi.product.version: pc-i440fx-xenial dmi.sys.vendor: QEMU To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/systemd/+bug/1800836/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp