Fri, 3 Jul 2020

4:22 PM - Overriding DNS server changes when dhcp is enabled.

By default, /etc/resolv.conf is updated when DHCP is enabled for an interface.  This is useful for WiFi or laptops where you frequently change networks. However, it can be problematic sometimes when different DNS servers are required. 

For static IP addresses, this is not modified automatically. 

Preventing Automatic Config Changes

Methods to try:

Use a static IP address

Make /etc/resolv.conf immutable

Override the dhclient configuration

Turn off resolvconf

Static IP

Simply edit your /etc/rc.conf and replace DHCP in your ifconfig line with a static IP configuration

Immutable resolv.conf

chflags schg /etc/resolv.conf

Override the dhclient config

place the following in /etc/dhclient.conf, but change the name of the interface as appropriate.  This example uses OpenDNS with an Intel Gigabit NIC. 

interface "em0" {

    supersede domain-name-servers,;


You will need to restart the dhclient for changes to take effect. 

service dhclient restart em0

Disable resolvconf(8)

Create a file 


Place this in the file