After some discussion, it appears that networkd is kinda of making a boolean (on|off) for IPV6 RA, when it's really a tri-state (on|off|kernel).
Upstream networkd indicates there is a tri-state; like so: Enable or disable IPv6 Router Advertisement (RA) reception support for the interface. Takes a boolean parameter. If true, RAs are accepted; if false, RAs are ignored, independently of the local forwarding state. When not set, the kernel default is used, and RAs are accepted only when local forwarding is disabled for that interface. When RAs are accepted, they may trigger the start of the DHCPv6 client if the relevant flags are set in the RA data, or if no routers are found on the link. While in netplan, we've only a boolean, which could be fine, except netplan defaults to AcceptRA=True which means we have no way of allowing the kernel configuration to work. Netplan needs to know if the yaml includes an accept-ra key, and if so, uses the value set (off or on); but if the yaml does not specify an accept-ra key, it should *NOT* render a default value. This allows hosts to defer the the kernel settings. This key was introduced as away to resolve a bug where "unconfigured" interfaces got an IPV6 address due to kernel setting and an IPV6 router present. https://bugs.launchpad.net/maas/+bug/1655440 -- 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/1732002 Title: cloud images in lxc get ipv6 address Status in nplan package in Ubuntu: New Status in systemd package in Ubuntu: New Bug description: I noticed that lxd (lxc list) reports that an lxc container has an ipv6 address in artful or bionic. It does not list this in xenial or zesty. I suspect this change occurred in the switch over to netplan/networkd. This may at first seem harmless or even desired, but note that the user configuration did not request ipv6 config, so its presence is a bug. $ for rel in xenial zesty artful bionic; do lxc launch ubuntu-daily:$rel $rel-demo; done Creating xenial-demo Starting xenial-demo .. Creating bionic-demo Starting bionic-demo $ sleep 10 $ lxc list $ lxc list +-------------+---------+----------------------+------------------------------------------------+------------+-----------+ | NAME | STATE | IPV4 | IPV6 | TYPE | SNAPSHOTS | +-------------+---------+----------------------+------------------------------------------------+------------+-----------+ | artful-demo | RUNNING | 10.75.205.208 (eth0) | fd42:eee5:7c43:3d62:3a42:611c:3f6f:1184 (eth0) | PERSISTENT | 0 | +-------------+---------+----------------------+------------------------------------------------+------------+-----------+ | bionic-demo | RUNNING | 10.75.205.187 (eth0) | fd42:eee5:7c43:3d62:6f4:155b:39cc:fc3d (eth0) | PERSISTENT | 0 | +-------------+---------+----------------------+------------------------------------------------+------------+-----------+ | xenial-demo | RUNNING | 10.75.205.143 (eth0) | | PERSISTENT | 0 | +-------------+---------+----------------------+------------------------------------------------+------------+-----------+ | zesty-demo | RUNNING | 10.75.205.123 (eth0) | | PERSISTENT | 0 | +-------------+---------+----------------------+------------------------------------------------+------------+-----------+ ## Here is the config that was provided by lxd $ lxc exec bionic-demo cat /var/lib/cloud/seed/nocloud-net/network-config version: 1 config: - type: physical name: eth0 subnets: - type: dhcp control: auto ## Here is the config that cloud-init rendered. $ lxc exec bionic-demo -- grep -v '^#' /etc/netplan/50-cloud-init.yaml network: version: 2 ethernets: eth0: dhcp4: true $ lxc exec bionic-demo cat /run/systemd/network/10-netplan-eth0.network [Match] Name=eth0 [Network] DHCP=ipv4 [DHCP] UseMTU=true RouteMetric=100 $ lxc exec bionic-demo -- systemctl status --no-pager --full systemd-networkd ● systemd-networkd.service - Network Service Loaded: loaded (/lib/systemd/system/systemd-networkd.service; enabled; vendor preset: enabled) Active: active (running) since Mon 2017-11-13 18:37:34 UTC; 8min ago Docs: man:systemd-networkd.service(8) Main PID: 118 (systemd-network) Status: "Processing requests..." Tasks: 1 (limit: 4915) Memory: 2.0M CPU: 19ms CGroup: /system.slice/systemd-networkd.service └─118 /lib/systemd/systemd-networkd Nov 13 18:37:34 bionic-demo systemd[1]: Starting Network Service... Nov 13 18:37:34 bionic-demo systemd-networkd[118]: eth0: Gained IPv6LL Nov 13 18:37:34 bionic-demo systemd-networkd[118]: Enumeration completed Nov 13 18:37:34 bionic-demo systemd[1]: Started Network Service. Nov 13 18:37:37 bionic-demo systemd-networkd[118]: eth0: DHCPv6 address fd42:eee5:7c43:3d62:6f4:155b:39cc:fc3d/128 timeout preferred 3600 valid 3600 Nov 13 18:37:37 bionic-demo systemd-networkd[118]: eth0: DHCPv4 address 10.75.205.187/24 via 10.75.205.1 Nov 13 18:37:37 bionic-demo systemd-networkd[118]: Not connected to system bus, ignoring transient hostname. Nov 13 18:37:39 bionic-demo systemd-networkd[118]: eth0: Configured Nov 13 18:38:09 bionic-demo systemd-networkd[118]: Could not set hostname: Method call timed out ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: nplan 0.30 ProcVersionSignature: Ubuntu 4.13.0-16.19-generic 4.13.4 Uname: Linux 4.13.0-16-generic x86_64 ApportVersion: 2.20.7-0ubuntu4 Architecture: amd64 Date: Mon Nov 13 18:27:53 2017 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) LANG=C.UTF-8 SourcePackage: nplan UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/nplan/+bug/1732002/+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
