[systemd-devel] systemd-resolved cannot survive router reinstall

[Anatol Pomozov]

Hi

On Mon, Aug 11, 2014 at 4:08 PM, Tom Gundersen <teg at jklm.no> wrote:
> On Sat, Aug 9, 2014 at 7:59 PM, Anatol Pomozov <anatol.pomozov at gmail.com> wrote:
>> I have a router where I experiment with OpenWRT. I sysupdate (i.e.
>> reinstall) openwrt regularly, once or twice a week. I also have an
>> Arch home server with the latest systemd. The machine connected via
>> ethernet cable.
>>
>> Every time I reboot router it looses information about current DHCP
>> leases and devices need to renew it. All devices (ipads/androids/music
>> center/..) are able to renew leases, openwrt ui shows valid new dhcp
>> leases. And only the Arch machine does not. It looks like other dhcp
>> clients have some kind of heartbeat message and renew leases when the
>> network is back. But not systemd-resolved. To restore the system back
>> I need to suspend/wakeup the machine and it is annoying.
>
> (I guess you mean systemd-networkd instead of systems-resolved)
>
> The way it should work is that if you lose the carrier on a link and
> then regain it we should renew the lease. If your machine is directly
> connected to the router and the router is rebooted, this should be
> triggered. So this sounds like a bug to me.
>
>> Is it a known issue? Is there any additional information I can provide?
>
> Not known, so may I ask you to start networkd from the command line as
> follows and send the output:
>
> # SYSTEMD_LOG_LEVEL=debug /lib/systemd/systemd-networkd
>
> In particular, point out at what point in the logs you restart the router.


Thanks for the instructions, here is the log
https://gist.github.com/anatol/cb497118cfad6af3dc60

The interesting entries are:
Aug 11 17:30:25 theserver systemd-networkd[32648]: ICMPv6 CLIENT:
Received Router Advertisment flags MANAGED/OTHER
Aug 11 17:30:25 theserver systemd-networkd[32648]: ICMPv6 CLIENT:
Received Router Advertisment flags MANAGED/OTHER
Aug 11 17:30:30 theserver systemd-networkd[32648]: ICMPv6 CLIENT:
Received Router Advertisment flags MANAGED/OTHER

Is it the "heartbeat" message from the router?


And here is my network config:

$ cat /etc/systemd/network/dhcp.network
[Match]
Name=en*

[Network]
DHCP=yes


The problem exists not only when I reinstall the router firmware but
also when I just reboot it. But I believe openwrt does the same in
both cases, it just drops all the leases and expects that device
reacquire DHCP leases when router gets online. systemd-networkd
restart "fixes" the problem but I expect that it should work without
systemd-networkd restart.