[Samba] Samba Mailing Lists: How to talk Samba nicely

[Michael Tokarev]

13.06.2023 22:57, Rowland Penny via samba пишет:

> OK, I have re-installed Ubuntu 22.04 and I 'think' I know what the problem is, I haven't worked out a fix yet though.
> 
> I have in /etc/resolv.conf:
> 
> nameserver 127.0.0.53
> options edns0 trust-ad
> search .
> 
> Yes that's right, just a dot for the search domain and I cannot find out how to change it, because /etc/resolv.conf is actually a symlink to another 
> file and I cannot find what writes that file :-(

This shouldn't be a problem by its own.  On a laptop without its own local domain
name it doesn't matter much which domain search to use, and "." is about right
anyway.

The problem seems to be the delays happening when the network isn't connected.
systemd-resolved (which is managed /etc/resolv.conf in this setup) does quite
good job to fail queries quickly when there's no connectivity (since any
sendto() calls will be failed immediately due to missing routes, and more,
since when network interfaces are down, it does not even try to send any
queries).

Someone here mentioned netplan. This is a worst thing to have/use. It is an
extra "unification" layer to convert yet another network configuration to
ifupdown (/etc/nstwork/ineterfaces) or to systemd-networkd or to something
else.

In order for systemd-resolved to know when interfaces come and go, it is best
to use it together with systemd-networkd (which also provides dhcp information
to systemd-resolved and other components such as system-timesyncd).

But even in case if systemd-networkd is not used, systemd-resolved should be
able to fail quickly instead of timing out every query.  Maybe it's worth
the effort to enable debugging and see what's going on there. It is not
supposed to work this way.

Thanks,

/mjt