Automatic Reconnect

Aleksander Morgado aleksandermj at chromium.org
Thu Nov 10 09:18:19 UTC 2022


Hey,

>
> I have a further question about all of this.
>
> My script works in that I see disconnect reported at 11:18:08 and then
> wan back up 11:18:13, but that is a fairly slow reconnection. My modem
> RG502Q-EA in Zyxel NR7101 supports automatic reconnect with something
> along the lines of 'qmicli -p -d /dev/cdc-wdm0 --wds-set-autoconnect
> enabled', and wouldn't that permit a faster reconnection? My Huawei
> B818-263 reconnected in between 1 and 2 seconds. But if we have the
> modem autoreconnect, then doesn't ModemManager need to monitor the
> reconnect, get the new IP settings, and pass on the new IP settings to
> netifd. And how would this work? Is this functionality already handled
> and is so how do I enable it? I notice at the moment that I the
> autoconnect settings seem to be disabled with the netifd ModemManager
> protocol.

QMI autoconnect is explicitly disabled during the MM connection
attempt because if IP settings change, we wouldn't be able to reapply
them properly because no one would notice the disconnection; that's
the main idea. Also, "autoconnection" is something not in MM's scope,
so that's why we manually try to manage the connectivity, also so that
errors in the connection attempt are properly propagated to the user.

>
> By the way my IFUP modification to the 10-report-down script already
> checks whether the interface was up before reporting the disconnect,
> and only brings the interface back up if it was previously up. So it
> already handles the state where the interface was brought down by the
> user (it will not reconnect then, since ifup was not true).
>

Ah, that could indeed work.

-- 
Aleksander


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