networkd does not enable ipv6 when requested

Bug #1877271 reported by Dan Streetman on 2020-05-07
This bug affects 1 person
Affects Status Importance Assigned to Milestone
systemd (Ubuntu)
Dan Streetman

Bug Description


if networkd is configured with ipv6 address but the 'disable_ipv6' sysctl is enabled, networkd does not enable it and set the ipv6 configuration.

[test case]



manually disable ipv6 for the interface:

ubuntu@lp1859862-b:~$ echo 1 | sudo tee /proc/sys/net/ipv6/conf/ens3/disable_ipv6

the interface should not contain any ipv6 addresses:

ubuntu@lp1859862-b:~$ ip -6 a show ens3

restart networkd; it should enable ipv6 as ipv6 addresses are configured, but it does not:

ubuntu@lp1859862-b:~$ sudo systemctl restart systemd-networkd
ubuntu@lp1859862-b:~$ ip -6 a show ens3

[regression potential]

any regression would likely result in failure to configure ipv6 addresses/routes.


this is needed only for Eoan.

this is fixed by commit 57ad76074670d4859e808a6aabd69fd6e58514c5, which is included starting in v243, so this is fixed in Focal and later.

this bug was introduced by a series of patches starting at 54a1a535bd60f13964bbddd8f381601e33e8e56f, which is included starting in v243, but was also pulled into Debian v242-4, and so included in Eoan. This bug is not present in earlier versions so is not needed in Xenial or Bionic.

[other info]

this is a follow on for the fix in bug 1859862.

Dan Streetman (ddstreet) on 2020-05-07
Changed in systemd (Ubuntu Eoan):
assignee: nobody → Dan Streetman (ddstreet)
status: New → In Progress
Changed in systemd (Ubuntu):
status: New → Fix Released
Changed in systemd (Ubuntu Eoan):
importance: Undecided → Medium
importance: Medium → Low

Hello Dan, or anyone else affected,

Accepted systemd into eoan-proposed. The package will build now and be available at in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See for documentation on how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, what testing has been performed on the package and change the tag from verification-needed-eoan to verification-done-eoan. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-eoan. In either case, without details of your testing we will not be able to proceed.

Further information regarding the verification process can be found at . Thank you in advance for helping!

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

Changed in systemd (Ubuntu Eoan):
status: In Progress → Fix Committed
tags: added: verification-needed verification-needed-eoan

All autopkgtests for the newly accepted systemd (242-7ubuntu3.9) for eoan have finished running.
The following regressions have been reported in tests triggered by the package:

nghttp2/unknown (armhf)
pulseaudio/unknown (armhf) (armhf)
csync2/unknown (armhf)
network-manager/unknown (armhf)
dovecot/unknown (armhf)
open-iscsi/unknown (armhf) (armhf)
asterisk/1:16.2.1~dfsg-2build2 (arm64)
tinyssh/unknown (armhf)
puppet/unknown (armhf)
corosync/unknown (armhf)
python-uinput/unknown (armhf)
nextepc/unknown (armhf)
debci/unknown (armhf)
pyudev/unknown (armhf)
cups/unknown (armhf)
umockdev/0.13.2-1 (armhf)
cockpit/unknown (ppc64el)
network-manager/1.20.4-2ubuntu2.2 (arm64)
nftables/unknown (armhf)
prometheus/unknown (armhf)
corosync-qdevice/unknown (armhf)
prometheus-bind-exporter/unknown (armhf)
python-systemd/unknown (armhf)
prometheus-alertmanager/unknown (armhf)
ndctl/unknown (armhf)
prometheus-apache-exporter/unknown (armhf)
dpdk/unknown (armhf)
nextepc/0.3.10+nods-3ubuntu1 (ppc64el)
dbus/unknown (armhf)
openssh/1:8.0p1-6build1 (armhf, amd64, i386, ppc64el, arm64, s390x)
openrazer/unknown (armhf)
gvfs/1.42.1-1ubuntu1 (arm64)
snapd/2.42.1+19.10 (i386)
prometheus-node-exporter/unknown (armhf)
prometheus-postgres-exporter/unknown (armhf)
python-dbusmock/unknown (armhf)
systemd/242-7ubuntu3.9 (ppc64el)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].


Thank you!

Dan Streetman (ddstreet) wrote :

root@lp1877271-e:~# dpkg -l systemd|grep systemd
ii systemd 242-7ubuntu3.7 amd64 system and service manager
root@lp1877271-e:~# echo 1 > /proc/sys/net/ipv6/conf/eth0/disable_ipv6
root@lp1877271-e:~# ip -6 a show eth0
root@lp1877271-e:~# systemctl restart systemd-networkd
root@lp1877271-e:~# ip -6 a show eth0

root@lp1877271-e:~# dpkg -l systemd|grep systemd
ii systemd 242-7ubuntu3.9 amd64 system and service manager
root@lp1877271-e:~# echo 1 > /proc/sys/net/ipv6/conf/eth0/disable_ipv6
root@lp1877271-e:~# ip -6 a show eth0
root@lp1877271-e:~# systemctl restart systemd-networkd
root@lp1877271-e:~# ip -6 a show eth0
112: eth0@if113: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000 link-netnsid 0
    inet6 2001:db8::100/64 scope global tentative
       valid_lft forever preferred_lft forever
    inet6 fe80::216:3eff:fe7d:babb/64 scope link tentative
       valid_lft forever preferred_lft forever

tags: added: verification-done verification-done-eoan
removed: verification-needed verification-needed-eoan
Launchpad Janitor (janitor) wrote :

This bug was fixed in the package systemd - 242-7ubuntu3.9

systemd (242-7ubuntu3.9) eoan; urgency=medium

  * d/p/lp1867375/0001-network-Allow-to-configure-GW-even-UseRoutes-false.patch,
    - Move gateway ignoring from UseRoutes= to UseGateway= (LP: #1867375)
   * d/p/lp1873607/0001-core-some-minor-clean-ups-modernizations.patch,
     - Avoid segfault during serialization (LP: #1873607)
   * d/p/lp1877271-network-drop-all-checks-of-ipv6_disabled-sysctl.patch:
     - enable ipv6 for interface when needed (LP: #1877271)
   * d/p/lp1860926-network-Change-IgnoreCarrierLoss-default-to-value-of.patch:
     - IgnoreCarrierLoss default to ConfigureWithoutCarrier (LP: #1860926)

 -- Dan Streetman <email address hidden> Fri, 08 May 2020 12:28:53 -0400

Changed in systemd (Ubuntu Eoan):
status: Fix Committed → Fix Released

The verification of the Stable Release Update for systemd has completed successfully and the package is now being released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

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