resolv.conf is changed when it passes for a while

Question

I set up /etc/resolv.conf

domain example.local
nameserver 127.0.0.1
nameserver 192.168.1.108

but,a days later..!?

It's changed!!

nameserver 192.168.1.1

192.168.1.1 is DHCPD

How to stop change it?

Answer 1

Is the machine sourcing it's IP address from DHCP?

If so, resolv.conf will be turned over by the DHCP client, to reflect the details in the lease it receives.

Take a look at the manpage for the DHCP client you are using. For instance dhcpcd has a -R flag which prevents this behaviour.

Answer 2

Most likely you have a dhcp-client service setup on your machine, it is rewriting /etc/resolv.conf with values it receives from the dhcp server.

Answer 3

to prevent dhcp client rewriting your settings you can put as well in dhclient.conf [ /etc/dhcp3 in debian, if you use isc's dhcp3-client ]

supersede domain-name "your.domain.name";
supersede domain-name-servers 127.0.0.1, 192.168.1.108 ;

this might look differently for other dhcp clients.