Diagnose DNS problem

[David Fletcher]

On Sun, 2022-10-02 at 14:55 +0100, Colin Law wrote:
> so any suggestions will be gratefully received.

I am absolutely no sort of an expert on this at all, but what I always
do with desktop systems is use the graphical network settings tool to
set either

A) fixed IPv(4+6) addresses, with the the IPv4 address outside of the
router's DHCP range of course, with a multiple choice of DNS servers, I
use the two OpenDNS options plus the 8.8.8.8 one. OpenDNS also provides
IPv6 service AFAIR

B) for laptops which are of course operated on various different LANs,
select from the graphical tool, use DHCP for ADDRESS ONLY then set up
the DHCP servers selection same as above.

For servers,
A) on my 20.04 server that runs my email etc. I used a text editor to
modify
/etc/netplan/00-installer-config.yaml
which is Ethernet connected, to set fixed IPv(4+6) addresses plus the
DNS servers

B) on a 22.04 server, which has a WiFi only connection, I edited
/etc/netplan/00-installer-config-wifi.yaml
to do something similar but of course it needs extra bits for
specifying the WiFi adaptor, network name and passcode. The syntax
appears to have changed for 22.04.

My configs have been hacked together from whatever the installer
produced, Google search, netplan error messages etc. but appear to work
to my satisfaction.

BTW I now have full fibre with fixed IP addresses and use an OpenWRT
router.

I'm happy to share the server configs if anybody wants to email me
privately.