I'm running Ubuntu 22.04.1 on a headless server and trying to change the DNS that the server uses. I set up the netplan .yaml file like this to use Cloudflare's servers:
network:
version: 2
renderer: networkd
ethernets:
enp0s31f6:
addresses:
- xxx.xxx.xxx.xxx/32
- xxxx.xxxx.xxx::2/64
routes:
- to: default
via: xxx.xxx.xxx.xxx
metric: 100
on-link: true
- to: ::/0
via: fe80::1
nameservers:
addresses:
- 1.1.1.1
- 2606:4700:4700::1111
- 1.0.0.1
- 2606:4700:4700::1001
After a sudo netplan apply, everything seemed copasetic. Except nslookup somewebsite.com showed that the DNS used was 8.8.8.8.
I traced the source of this, I think, to the /etc/resolv.conf file, which is not a symbolic link and which looks like this:
# Dynamic resolv.conf(5) file for glibc resolver(3) generated by resolvconf(8)
# DO NOT EDIT THIS FILE BY HAND -- YOUR CHANGES WILL BE OVERWRITTEN
# 127.0.0.53 is the systemd-resolved stub resolver.
# run "systemd-resolve --status" to see details about the actual #nameservers.
#nameserver 127.0.0.53
nameserver 8.8.8.8
Not only does that file say that it's not to be edited, it in fact can't be edited. And I'm sure that, if I were to edit it, it would be overwritten (by resolvconf, I assume) with that Google nameserver.
I'm now in a position where everything checks out except the actual DNS being used, which is stubbornly stuck on 8.8.8.8.
For example, sudo networkctl status enp0s31f6 returns this:
● 2: enp0s31f6
Link File: /usr/lib/systemd/network/99-default.link
Network File: /run/systemd/network/10-netplan-enp0s31f6.network
Type: ether
State: routable (configured)
Online state: online
Path: pci-0000:00:1f.6
Driver: e1000e
Vendor: Intel Corporation
Model: Ethernet Connection (2) I219-LM
HW Address: xx:xx:xx:xx:xx:xx (Fujitsu Technology Solutions GmbH)
MTU: 1500 (min: 68, max: 9000)
QDisc: pfifo_fast
IPv6 Address Generation Mode: eui64
Queue Length (Tx/Rx): 1/1
Auto negotiation: yes
Speed: 1Gbps
Duplex: full
Port: tp
Address: xxx.xxx.xxx.xxx
xxxx:xxx:xx:xxxx::2
xxxx::xxxx:xxx:xxxx:xxxx
Gateway: xxx.xxx.xxx.xxx
xxx.xxx.xxx.xxx
fe80::1
DNS: 1.1.1.1
1.0.0.1
2606:4700:4700::1111
2606:4700:4700::1001
Activation Policy: up
Required For Online: yes
DHCP6 Client DUID: DUID-EN/Vendor:0000ab11edfd2edd2491a9410000
And sudo resolvctl status gives this:
Global
Protocols: -LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
resolv.conf mode: foreign
Current DNS Server: 1.1.1.1
DNS Servers: 1.1.1.1
Fallback DNS Servers: 1.0.0.1
Link 2 (enp0s31f6)
Current Scopes: DNS
Protocols: +DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
Current DNS Server: 1.1.1.1
DNS Servers: 1.1.1.1 1.0.0.1 2606:4700:4700::1111 2606:4700:4700::1001
Link 8 (wg0)
Current Scopes: none
Protocols: -DefaultRoute +LLMNR -mDNS -DNSOverTLS DNSSEC=no/unsupported
So everything I look at tells me that 1.1.1.1 is the primary DNS for my server. Except nslookup askubuntu.com which stubbornly always returns this:
Server: 8.8.8.8
Address: 8.8.8.8#53
Non-authoritative answer:
Name: askubuntu.com
Address: 151.101.65.69
Name: askubuntu.com
Address: 151.101.193.69
Name: askubuntu.com
Address: 151.101.129.69
Name: askubuntu.com
Address: 151.101.1.69
I verified that 8.8.8.8 is indeed being used by running sudo tcpdump -n -vv -i enp0s31f6 -W 1200 | grep google.com in one window while running nslookup google.com in another.
How can I get my server to stop using 8.8.8.8 and start using the DNS I've been trying to get it to run?
