Wietse Venema:
> Steffen Nurpmeso:
> > Steffen Nurpmeso wrote in
> > <20220929213725.gar4l%[email protected]>:
> > |Viktor Dukhovni wrote in
> > | <[email protected]>:
> > ||On Thu, Sep 29, 2022 at 07:25:48PM +0200, Steffen Nurpmeso wrote:
> > ||> But on FreeBSD (only VM here for some years) on fresh install
> > ||> i always have sendmail hang minutes upon startup (i interrupt to
> > ||> come to login, which thankfully works), because it is of the
> > ||> opinion that the hostname is not valid on the network, or
> > ||> something. I do not have the same problem with postfix though.
> > ||
> > ||By design. As Wietse has explained from time to time, Postfix starts up
> > ||and delivers local mail even when the network is down. Delivering mail
> > ||to remote systems of course requires some form of connectivity (dialup
> > ||uucp could still be used in principle).
> > |
> > |I think it has something to do with uname(2) that is used in order
> > |to query the nodename of the box. For my little mailer (MUA)
> >
> > That is, i have seen such hangs with my MUA -- whether sendmail
> > hangs due to this, i do not know.
>
> Sendmail hangs because it uses the nsswitch mechanism which may do
> DNS lookups, as it does in your example.
I hate to post incorrect info, so here is a correction. When the
nsswitch lookup result (typically from /etc/hosts) has no name
with '.', then Sendmail will query the DNS directly, pausing 60s
after a DNS lookup failure.
Wietse
