1: Resolvconf writes its dynamic resolv.conf file at /run/resolvconf/resolv.conf
. /etc/resolv.conf
is a symbolic link to the latter location. If you want to use a static resolv.conf file, simply replace the /etc/resolv.conf symbolic link with a file. This is currently supported but not recommended.
2: As I understand it, the affected machine is running Ubuntu Server edition. In that case it configures interfaces using the ifup
program whose configuration file is /etc/network/interfaces
. For interfaces configured via the dhcp
method, ifup
(normally) uses dhclient
from the isc-dhcp-client
package. Dhclient receives nameserver information from the DHCP server and its hook script /etc/dhcp/dhclient-enter-hooks.d/resolvconf
sends this information to resolvconf
which puts it into resolv.conf
.
One thing you can do is edit /etc/resolvconf/interface-order
such that eth0.dhcp
comes before eth0.dhclient
. (I assume that the relevant interface is eth0
.) If you have the default interface-order
you can, for example, just add a line eth0.dhcp
before the line eth*
.
--- interface-order_ORIG 2012-11-06 10:12:47.630529145 +0100
+++ interface-order 2012-11-06 10:13:16.410529800 +0100
@@ -9,6 +9,7 @@
hso*
em+([0-9])?(_+([0-9]))*
p+([0-9])p+([0-9])?(_+([0-9]))*
+eth0.dhcp
eth*
ath*
wlan*
Then add a dns-nameservers
line to the iface eth0
stanza in /etc/network/interfaces
with the correct nameserver address.
iface eth0 inet dhcp
dns-nameservers 1.2.3.4
Because eth0.dhcp
comes before eth0.dhclient
, the correct nameserver address will be included in resolv.conf
before the incorrect one.
Another way to override the unwanted behavior of including the DHCP-server-provided nameserver address is to edit the dhclient hook script. E.g., you can add a line like the following (where 1.2.3.4 is a nameserver address you would like to discard).
--- resolvconf_ORIG 2012-03-29 22:37:14.000000000 +0200
+++ resolvconf 2012-11-05 20:53:33.312681077 +0100
@@ -54,6 +54,7 @@
fi
shopt -s nocasematch
for nameserver in $new_dhcp6_name_servers ; do
+ [ "$nameserver" = "1.2.3.4" ] && continue
Yet another possibility (a slightly crude one, since it's completely static) is to add a nameserver option to /etc/resolvconf/resolv.conf.d/head
.
3: Setting DNS nameserver addresses has gotten more complicated because machines are becoming mobile, are getting more and more interfaces and static configuration is gradually being replaced by autoconfiguration.
Turns out this was a simple not having rebooted problem.
I had changed my /etc/network/interfaces
to set the static interface, but never rebooted. This left dhclient
running for eth1
, which eventually went to renew the DHCP address. Killing dhclient
fixed the problem, and with the interfaces
file defining a static IP, it was not started on the next reboot.
Best Answer
Just press Ctrl+Alt+T on your keyboard to open Terminal. When it opens, run the command below.
You will see this:
Replace it with:
Then restart networking components.