On Thu 17 Mar 2022 at 12:12:28 (+0000), Thomas Pircher wrote
>
> Cool. If you just type resolvectl, it will show you which information it
> got on each interface.
This is machine F, where /etc/resolv.conf is a file, containing 192.168.1.1 :
$ resolvectl
Global
Protocols: +LLMNR +mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: foreign
Current DNS Server: 192.168.1.1
DNS Servers: 192.168.1.1
Link 2 (enp2s2)
Current Scopes: none
Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Link 5 (wlp2s4)
Current Scopes: LLMNR/IPv4 LLMNR/IPv6
Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
$ host www.google.com
www.google.com has address 142.250.138.105
www.google.com has address 142.250.138.103
www.google.com has address 142.250.138.106
www.google.com has address 142.250.138.99
www.google.com has address 142.250.138.104
www.google.com has address 142.250.138.147
www.google.com has IPv6 address 2607:f8b0:4000:80e::2004
$ host www.lionunicorn.co.uk
www.lionunicorn.co.uk has address 149.255.60.149
$
Those responses were instantaneous. (I don't think I should expect
resolvectl query to work here.)
And this is machine R, with systemd-resolved running:
$ ls -l /etc/resolv.conf
lrwxrwxrwx [ … ] /etc/resolv.conf -> ../run/systemd/resolve/stub-resolv.conf
$ resolvectl
Global
Protocols: +LLMNR +mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: stub
Link 2 (enp1s0)
Current Scopes: none
Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Link 4 (wlan0)
Current Scopes: DNS LLMNR/IPv4
Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 192.168.1.1
DNS Servers: 192.168.1.1
$ host www.google.com
www.google.com has address 142.251.32.196
www.google.com has IPv6 address 2607:f8b0:4023:1002::63
www.google.com has IPv6 address 2607:f8b0:4023:1002::67
www.google.com has IPv6 address 2607:f8b0:4023:1002::93
www.google.com has IPv6 address 2607:f8b0:4023:1002::69
;; connection timed out; no servers could be reached
$ resolvectl query www.google.com
www.google.com: 2607:f8b0:4000:805::2004 -- link: wlan0
142.251.46.132 -- link: wlan0
Your machine F seems to resolve almost entirely IPv4 addresses for that host.
But your machine R resolves almost exclusively IPv6 addresses for it.
Could there be an identical hostname assigned to both IPv4 and IPv6 interfaces?
In general you want DNS queries to resolve with less than 500msec network latency. Above 1500 to 1700 msec the applications start breaking and network timeouts are hit.
Trimming the rest of your email...
-- Information acquired via protocol DNS in 33.6ms.
-- Data is authenticated: no
.........
Cheers,
David.