My NetworkManager connects to the internet but I do not have any internet access due to a bad DNS configuration. I do not have much experience with DNS settings, but it appears the issue is with systemd-resolved. I can ping IP addresses directly (e.g. 8.8.8.8) and get a response normally, but I cannot resolve domains when using the default configuration below. I have tried a symlink to the three configuration modes listed in the systemd-resolved docs, but none of them work.
Cannot resolve any domain with the following, but I can ping IPs (tried a bunch and they all work) without any issues.
# /etc/resolv.conf
nameserver 127.0.0.53
options edns0 trust-ad
I also get timeout errors when using dig or host.
; <<>> DiG 9.16.1-Ubuntu <<>> www.ubuntu.com
;; global options: +cmd
;; connection timed out; no servers could be reached
I can get domain resolution and connect to the internet by changing the resolv.conf nameserver to 8.8.8.8, but resolution takes a long time, with a web page taking >1 min to load even with network speed tests reporting over 100 mbps and ping <30 ms on the same machine.
The configuration below works, sort of, with really slow response times
# /etc/resolv.conf
nameserver 8.8.8.8
options edns0 trust-ad
Additional info that might be helpful
Like I said, I am new to these systems and I am struggling to troubleshoot the issue. Below is everything that I think might be useful. All outputs below are using nameserver 127.0.0.53
Ubuntu 20.04.3 LTS
Output of systemd-resolve --status
Global
LLMNR setting: no
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
DNSSEC NTA: 10.in-addr.arpa
16.172.in-addr.arpa
168.192.in-addr.arpa
17.172.in-addr.arpa
18.172.in-addr.arpa
19.172.in-addr.arpa
20.172.in-addr.arpa
21.172.in-addr.arpa
22.172.in-addr.arpa
23.172.in-addr.arpa
24.172.in-addr.arpa
25.172.in-addr.arpa
26.172.in-addr.arpa
27.172.in-addr.arpa
28.172.in-addr.arpa
29.172.in-addr.arpa
30.172.in-addr.arpa
31.172.in-addr.arpa
corp
d.f.ip6.arpa
home
internal
intranet
lan
local
private
test
Link 3 (ipv6leakintrf0)
Current Scopes: DNS
DefaultRoute setting: yes
LLMNR setting: yes
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
Current DNS Server: ::1
DNS Servers: ::1
DNS Domain: ~.
Link 2 (wlo1)
Current Scopes: none
DefaultRoute setting: no
LLMNR setting: yes
MulticastDNS setting: no
DNSOverTLS setting: no
DNSSEC setting: no
DNSSEC supported: no
# /etc/systemd/resolved.conf
[Resolve]
#DNS=
#FallbackDNS=
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#DNSOverTLS=no
#Cache=no-negative
#DNSStubListener=yes
#ReadEtcHosts=yes
# NetworkManager configuration: /etc/NetworkManager/NetworkManager.conf (lib: 10-dns-resolved.conf, 20-connectivity-ubuntu.conf, no-mac-addr-change.conf) (run: 10-globally-managed-devices.conf) (etc: default-wifi-powersave-on.conf)
[main]
# rc-manager=symlink
# auth-polkit=true
# dhcp=internal
dns=systemd-resolved
plugins=ifupdown,keyfile
[connectivity]
uri=http://connectivity-check.ubuntu.com/
[ifupdown]
managed=false
[logging]
# backend=journal
# audit=true
[device]
wifi.scan-rand-mac-address=no
[device-mac-addr-change-wifi]
match-device=driver:rtl8723bs,driver:rtl8189es,driver:r8188eu,driver:8188eu,driver:eagle_sdio,driver:wl
wifi.scan-rand-mac-address=no
[connection]
wifi.powersave=3
# no-auto-default file "/var/lib/NetworkManager/no-auto-default.state"
The system log on startup
Starting Network Name Resolution...
sisyphus systemd-resolved[6024]: Positive Trust Anchors:
sisyphus systemd-resolved[6024]: . IN DS 20326 8 2 e17f45b80b8f1d39a95f0b0d7c45a08458e880409bbc683457104237c7f8ec8d
sisyphus systemd-resolved[6024]: Negative trust anchors: 10.in-addr.arpa 16.172.in-addr.arpa 17.172.in-addr.arpa 18.172.in-addr.arpa 19.172.in-addr.arpa 20.172.in-addr.arpa 21.172.in-addr.arpa 22.172.in-addr.arpa 23.172.in-addr.arpa 24.172.in-addr.arpa 25.172.in-addr.arpa 26.172.in-addr.arpa 27.172.in-addr.arpa 28.172.in-addr.arpa 29.172.in-addr.arpa 30.172.in-addr.arpa 31.172.in-addr.arpa 168.192.in-addr.arpa d.f.ip6.arpa corp home internal intranet lan local private test
sisyphus systemd-resolved[6024]: Using system hostname 'sisyphus'.
The system log in debug mode outputs the following, switching between UDP and TCP protocols.
Transaction 33247 for <ntp.ubuntu.com IN A> scope dns on ipv6leakintrf0/*.
systemd-resolved[4805]: Using feature level TCP for transaction 33247.
systemd-resolved[4805]: Sending query via TCP since UDP isn't supported.
systemd-resolved[4805]: Using feature level TCP for transaction 33247.
systemd-resolved[4805]: Connection failure for DNS TCP stream: Connection refused
systemd-resolved[4805]: Retrying transaction 33247.
