connection closes every 10 minutes

[Marco Fioretti]

Hi,

I honestly don't know if the old modem had an integrated router, and I
have already disposed of it. What I am sure of is that I had NOT
changed anything in its settings for many months, if not years, and
everything was working without problems until a few weeks ago, when I
posted here.

Marco

Il giorno mar 27 apr 2021 alle ore 23:49 Joseph Tam
<jtam.home at gmail.com> ha scritto:
>
> On Mon, 26 Apr 2021, Marco Fioretti wrote:
>
> > 3) a few days ago I received a new modem from my ISP, as part of their
> > network upgrade operations
> >
> > 4) more or less in the same moment the problem I reported here
> > disappeared. Now mutt stays connected even 24 hours without losing
> > connection.
> >
> > I am NOT 100% sure that the problem disappeared AFTER the change of
> > modem. That happened during a few chaotic days, both work- and
> > family-wise, so I did not take notes. And modems may have nothing to
> > do at all with the disconnections. But now the problem is not there
> > anymore, I have no clue what may have happened, and if anybody can
> > guess... thanks in advance.
>
> Does this modem also have an integrated router?  These units tend to
> act as NAT gateways/firewalls that keep track of "active" sessions by
> tracking external/interface NAT address mappings.  Cheap or older one
> could have TTL on these entries i.e. if no traffic is detected within
> a time window, it is discarded, and appearing as if the endpoints had
> disconnected.  I guess it could also happen if the state tracking
> tables has limited memory and your internal network is busy, like a family
> member opening up a P2P application.
>
> Just a hypothesis.
>
> >> Apr 12 16:12:49 SERVERNAME dovecot: imap(ACCOUNTNAME): Logged out in=164 out=757
>
> However, my hypothesis wouldn't produce this.  This is a active
> logout.
>
> Joseph Tam <jtam.home at gmail.com>