Ubuntu 18.04: systemd-resolved -- crashing or failing to start properly...

[Tom H]

On Mon, Jun 3, 2019 at 6:24 PM Robert Heller <heller at deepsoft.com> wrote:
> At Sat, 1 Jun 2019 12:31:11 +0200 "Ubuntu user technical support, not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
>> On Sat, Jun 1, 2019 at 2:29 AM Robert Heller <heller at deepsoft.com> wrote:


>>> I have an *intermittent* problem with systemd-resolved. It is
>>> either crashing or fails to start properly. The sympton is that
>>> when I go to do an update (eg apt-get update), I get name
>>> resolver errors to the *local* (LAN only) mirror host. Doing a
>>> "systemctl restart systemd-resolved" cures the problem. I am not
>>> sure exactly what is going on, but it appears that for some
>>> reason systemd-resolved is not seeing (or using) the *local* LAN
>>> DNS server (bind9 running on a CentOS 6 server). For *all* of the
>>> Ubuntu 18.04 machines, *I* would *rather* not have
>>> systemd-resolved running at all and just have /etc/resolve.conf
>>> reference the CentOS 6 server and bind9 running there. (I have
>>> configured things on the DRBL server to do just that.) It is
>>> already a cacheing DNS server for the whole LAN and provides
>>> local DNS for the LAN, including intranet services (NFS server,
>>> LDAP server, LAN-only web services, etc.). The problem is an
>>> issue on the laptops and one workstation, and only really affects
>>> LAN-only web services (which includes the local repo mirror) --
>>> the NFS mounts and LDAP configuration use the hard IP address of
>>> the server(s) in question.
>>
>> [ It's "/etc/resolv.conf" not "/etc/resolve.conf" but I assume
>> that this is an email typo not an on-filesystem one ]
>
> Yes...
>>
>> Are you feeding "systemd-resolved" the LAN DNS server? What's the
>> output of "resolvectl"?
>
> systemd-resolved should be get parameters via DHCP from the DHCP server:
>
> (From the dhcpd.conf file on the CentOS 6 machine:
>
> option domain-name "wendellfreelibrary.org";
> option domain-name-servers 192.168.1.251, 8.8.8.8, 8.8.4.4;
> option broadcast-address 192.168.1.255;
> option routers 192.168.1.251;
>
> )

OK.


> There is no resolvectl program. It does not appear to be installed
> on my Ubuntu 18.05 system.

Sorry. Then "systemd-resolve --status" which has become "resolvectl
status" in later versions.