On Mon, Oct 5, 2020 at 1:33 AM Daniel Wagner <wagi@monom.org> wrote:
On Sat, Oct 03, 2020 at 05:00:17PM -0500, KeithG wrote:
> I read through the code a bit more closely and it appears that the
> BackgroundScanning is just for wifi. Do I have this correct?

Correct.

> If so, why
> does connman continually make the unused eth0 interface go up and down and
> spam the log with messages that it made it go up and down?

I am pretty sure this is not ConnMan's doing.

> It appears that
> it does this every 15 minutes. This happens whether or not the 'single
> connected technology' is selected or not. I would think that if a single
> connected technology was selected and it was connected on the wifi that it
> would be quiet and ignore the other interfaces until it lost a connection
> on the wifi...

Do you have any other network related daemons running?

Thanks,
Daniel

To answer your questions:

I do not believe that I have any other network daemons loaded or running on either the laptops or the RPis. I have uninstalled wpa_supplicant on all platforms and have disabled systemd-networkd and dhcpcd. In addition, on the laptop, I disabled NetworkManager as I am running Gnome and I was unable to remove it without removing a bunch of other stuff I need.

# systemctl status systemd-networkd
● systemd-networkd.service - Network Service
     Loaded: loaded (/usr/lib/systemd/system/systemd-networkd.service; disabled; vendor preset: enabled)
     Active: inactive (dead)
       Docs: man:systemd-networkd.service(8)

Since I do not have wpa_supplicant installed, I find it strange that the only way I was able to get any of these devices to scan and reconnect when the SSID went away and returned was to have 'BackgroundScanning=true'. If this was left as default (commented out), I can see on both monitor-iwd and monitor-connman that the interface goes away and the computer just sits there and does nothing. Never rescans. Same on the RPIs and Laptop. I let it sit for 30 minutes and nothing ever happens. As soon as I made this one edit and restarted connman, if I reboot the router, it will reconnect almost immediately.

As for the eth0 up and down, it looks like it is being controlled by connman. At least journalctl thinks so:

Oct 05 08:18:53 rune64 connmand[4313]: eth0 {update} flags 36866 <DOWN>
Oct 05 08:18:53 rune64 connmand[4313]: eth0 {newlink} index 3 address B8:27:EB:07:99:85 mtu 1500
Oct 05 08:18:53 rune64 connmand[4313]: eth0 {newlink} index 3 operstate 2 <DOWN>
Oct 05 08:18:53 rune64 connmand[4313]: eth0 {update} flags 36867 <UP>
Oct 05 08:18:53 rune64 connmand[4313]: eth0 {newlink} index 3 address B8:27:EB:07:99:85 mtu 1500
Oct 05 08:18:53 rune64 connmand[4313]: eth0 {newlink} index 3 operstate 2 <DOWN>
Oct 05 08:34:20 rune64 connmand[4313]: eth0 {update} flags 36866 <DOWN>
Oct 05 08:34:20 rune64 connmand[4313]: eth0 {newlink} index 3 address B8:27:EB:07:99:85 mtu 1500
Oct 05 08:34:20 rune64 connmand[4313]: eth0 {newlink} index 3 operstate 2 <DOWN>
Oct 05 08:34:20 rune64 connmand[4313]: eth0 {update} flags 36867 <UP>
Oct 05 08:34:20 rune64 connmand[4313]: eth0 {newlink} index 3 address B8:27:EB:07:99:85 mtu 1500
Oct 05 08:34:20 rune64 connmand[4313]: eth0 {newlink} index 3 operstate 2 <DOWN>

Spams the log with this.