On Sat, 10 Mar 2018 23:13:21 -0800 Rob Leslie <r...@mars.org> wrote:
> The fix for this bug broke the IPv6 networking on one of my systems.
> When the RA does not include any MTU information, this patch causes no IPv6
> default route to be added at all, leaving the system without IPv6
> connectivity. The journal in this case shows:
> systemd-networkd: eno1: Failed to get default router MTU from RA: No
> data available
> A workaround is to add MTU information to the RA from the router, but I don’t
> think this should be necessary.
We can confirm that the change broke IPv6 on all our updated Stretch
2018-03-13T08:25:24.671634+01:00 machine.example.com systemd-networkd:
ens192: Failed to get default router MTU from RA: No data available
$ sysctl -a |grep "accept_ra = "
net.ipv6.conf.all.accept_ra = 1
net.ipv6.conf.default.accept_ra = 1
net.ipv6.conf.ens192.accept_ra = 0
net.ipv6.conf.lo.accept_ra = 1
The sysctl output shows that "accept_ra" is enabled for all entries except
for the first physical interface.
Manually setting "accept_ra" to "1" allows us to get a default route,
but restarting systemd-networkd changes it back to 0.