connection closes every 10 minutes

[Joseph Tam]

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>