CentOS 7 NetworkManager Keeps Overwriting /etc/resolv.conf

Oh Dear! monitors your entire site, not just the homepage. We crawl and search for broken pages and mixed content, send alerts when your site is down and notify you on expiring SSL certificates.

Start your free 10 day trial! »

Image of Mattias Geniar

Mattias Geniar, September 01, 2015

Follow me on Twitter as @mattiasgeniar

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.



Want to subscribe to the cron.weekly newsletter?

I write a weekly-ish newsletter on Linux, open source & webdevelopment called cron.weekly.

It features the latest news, guides & tutorials and new open source projects. You can sign up via email below.

No spam. Just some good, practical Linux & open source content.