Debian – set the Debian box to use OpenDNS nameservers if it uses DHCP

debiandhcpdnsnetworking

I have a Debian box with this in /etc/network/interfaces:

auto eth0
allow-hotplug eth0
iface eth0 inet dhcp

auto wlan0
iface wlan0 inet dhcp
    wpa-ssid NetworkName
    wpa-psk NetworkPass

and this in /etc/resolv.conf (presumably this stuff gets pulled from my Cisco router automatically?)

domain cable.myisp.com
search cable.myisp.com
nameserver isp_nameserver_ip1
nameserver isp_nameserver_ip2

I'd like to use OpenDNS (or Norton Secure DNS, basically just some other DNS server), so can I just remove the first two lines from /etc/resolv.conf and update the last two with new nameserver IP addresses? Is there anything else I'd need to do?

I can change the settings on my router easy enough but is it possible to do this within the OS?

Best Answer

This site suggests you can put

option domain-name-servers x.y.z.1 x.y.z.2

into dhclient.conf. This will prevent dhclient from clobbering resolve.conf with your dhcp provided nameservers.

Personally I take the route you mention and tell my dhcp server on the router to provide the nameservers I want that way all of my machines get the benefit and not just one server.

Related Solutions

Debian – Wait for a network device to come up before bringing another network device up on boot

Hmm.. Just a thought. But, I do assume your using DHCP on your Wi-Fi network. Therefore, you wouldn't have an IP address until your network is fully up.

So, let's just have a little while loop.

while [ "$(ifconfig wlan0 | grep inet | grep 192.168.)" = "" ];  do sleep 1; done

The 192.168. should be replaced with your standard range. Now it would check every second once if you're already having a connection and as soon as you're having a connection via wifi you can follow up directly with ifup eth0

Debian – Can not set static DNS on debian

Because the By default jessie network configured via DHCP

you have multi solution

sol 1:
sudo update-rc.d dhcpcd remove

sol 2:
sudo nano /etc/dhcpcd.conf or /etc/dhcp/dhclient.conf

adding the following command

 nodhcp

and in file /etc/network/interfaces must change the lines in the following way:

iface lo inet loopback
auto eth0
any config .......

normal config for jessie

edit dhcpcd.conf file

sudo nano  /etc/dhcpcd.conf

and add at the end of the file

interface eth0
static ip_address=192.168.1.56

#gateway
static routers=192.168.1.210 

static domain_name_servers=8.8.8.8