[Samba] Winbind, cached logons and 'user persistency'...

[L.P.H. van Belle]

Hai Marco, 

> Yesterday i've updated my main switch, disconnecting for a 
> brief lag of time all my ''infrastructutes''.
> 
> My SMTP server (exim) start to complain about 'unroutable addresses':
> 
>  2019-01-16 18:32:40 1gjp3Q-0006aw-TG <= root at sv.lnf.it 
> H=(3jane.sv.lnf.it) [10.5.1.13] P=esmtp S=655 
> id=20190116173240.C20003CE035A at 3jane.sv.lnf.it
>  2019-01-16 18:33:45 1gjp3Q-0006aw-TG ** gaio at fvg.lnf.it 
> <root at sv.lnf.it> F=<root at sv.lnf.it>: Unrouteable address
> 
> my SMTP server is a DM, configured with winbind and cached/offline
> logons. SMTP server use 'nss' as final delivery rules (eg, user that
> exist in NSS are delivered).
> After some minutes i've reconnected and powered up the new switch, and
> all come back as usual.
> 
> 
> So seems that disconnecting temporarly the DM from the DCs, lead to
> 'user not found' error, like as users ''desappear'' from NSS.
> In winbind logs nothing get printed.
> 
> 
> Why?!

Your Exim is not complaining about users, but is complaining about a non deliverable message,
due to not reaching the destination ip adres. ( Unrouteable address ) 

As far i can tell winbind/nss resolved the user by cache, exim tried to deliver but was unsuccessfull. 
If the user wasnt found, you would have seen undeliverable adress so something like that. 

So looks normal to me. 

Greetz, 

Louis