= Ubuntu/resolv.conf =
<<TableOfContents()>>

{{{
resolv.confが上書きされるときにDNSを設定するにはどうすればよいですか？
}}}

https://qastack.jp/unix/128220/how-do-i-set-my-dns-when-resolv-conf-is-being-overwritten

DNSの制御を取り戻す

== 20.04LTS ==
 /etc/resolvconf は存在しない。
 dnsmasq もない。

== systemd-resolved ==
https://thr3a.hatenablog.com/entry/20180711/1531285176

Ubuntu 17.04以降ではsystemd-resolvedがデフォルトで動作しているため、/etc/resolv.confを書き換えても変更されない

{{{
$ cat /etc/systemd/resolved.conf 
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU Lesser General Public License as published by
#  the Free Software Foundation; either version 2.1 of the License, or
#  (at your option) any later version.
#
# Entries in this file show the compile time defaults.
# You can change settings by editing this file.
# Defaults can be restored by simply deleting this file.
#
# See resolved.conf(5) for details

[Resolve]
#DNS=
#FallbackDNS=
#Domains=
#LLMNR=no
#MulticastDNS=no
#DNSSEC=no
#DNSOverTLS=no
#Cache=no-negative
#DNSStubListener=yes
#ReadEtcHosts=yes

}}}

{{{
[Resolve]
DNS=8.8.8.8 8.8.4.4

で再起動して反映

systemctl restart systemd-resolved

}}}

== NetworkManager ==
NetworkManagerが設定しているらしい。

{{{
3.ネットワークマネージャー：

構成ファイル

/etc/NetworkManager/*

DNSを無効にする

$ cat /etc/NetworkManager/conf.d/no-dns.conf
[main]
dns=none

}}}

== DHCP オーバーライド ==
https://wiki.ubuntu.com/OverrideDNSServers