CentOS 7 NetworkManager Keeps Overwriting /etc/resolv.conf

In CentOS or Red Hat Enterprise Linux (RHEL) 7, you can find your

/etc/resolv.conf

file, which holds all nameserver configurations for your server, to be overwritten by the NetworkManager.

If you check the content of

/etc/resolv.conf

, it may look like this.

$ cat /etc/resolv.conf
# Generated by NetworkManager
search mydomain.tld
nameserver 8.8.8.8

The NetworkManager will assume it has the rights to control

/etc/resolv.conf

, if it finds a DNS related configuration in your interface configuration file.

$ grep DNS /etc/sysconfig/network-scripts/ifcfg-*
DNS1="8.8.8.8"
IPV6_PEERDNS="yes"

To prevent Network Manager to overwrite your

resolv.conf

changes, remove the DNS1, DNS2, ... lines from

/etc/sysconfig/network-scripts/ifcfg-*

.

Now, you can manually change the

/etc/resolv.conf

file again, and you should be good to go. NetworkManager will no longer overwrite your DNS nameserver configurations.

参考文章：https://ma.ttias.be/centos-7-networkmanager-keeps-overwriting-etcresolv-conf/