Bug#827424: systemd-networkd IPv6AcceptRouterAdvertisements doesn't work

[Andreas Henriksson]

Control: tags -1 + moreinfo

Hello Michael Berg,

On Wed, Jun 15, 2016 at 06:23:06PM -0600, Michael Berg wrote:
> Package: systemd
> Version: 230-2
> Severity: normal
> 
> According on the systemd.network manual page:
> IPv6AcceptRouterAdvertisements=
>     Force the setting of the accept_ra ...
>     Takes a boolean.
>     ... note that systemd's setting of 1
>     corresponds to kernel's setting of 2.
> 
> This documented behavior is not the behavior that I am seeing.
> IPv6AcceptRouterAdvertisements always results in accept_ra=1.
[...]

I wonder if maybe you're finding the wording a bit confusing because
I think you're misinterpretting things.

The systemd networkd has it's own router advertisement implementation
and doesn't rely on the kernels default. Also I think networkd
handles things per-link which means that looking at system-global
settings is probably not very useful.

If you look at a particular link you'll likely see that it has
accept_ra=0 (eg. disabled) whenever you use systemd networkd
to handle RA on that link.
Try checking /proc/sys/net/ipv6/conf/$INTERFACE/accept_ra
You'll notice "all" has the system-global setting you're seeing
with sysctl, but that a particular link/interface has another
which makes it deviate from the global default.

I'm not a native english speaker myself by my interpretation of
"corresponds to" is NOT "uses", but rather "similar but uses a
completely separate implementation".


Unfortunately it's not clear to me from reading the rest of your bug
report what your original problem really was.

Regards,
Andreas Henriksson