Linux / UNIX set the DNS from the command line

by nixCraft on December 19, 2007 · 14 comments· last updated at December 20, 2007

Q. I just got Linux installed on my system. I'm able to connect to internet via IP address only. I'm not able to find out information about setting up new DNS sever ip under Linux. How do I configure primary and secondary DNS via terminal / shell prompt?

A. Under Linux / UNIX / BSD operating system, you need to edit the /etc/resolv.conf file and add the line:

nameserver {IP-OF-THE-DNS-1}
nameserver {IP-OF-THEISP-DNS-SERVER-2}

Login as the root, enter:
# vi /etc/resolv.conf
OR
$ sudo vi /etc/resolv.conf
Modify or enter nameserver as follows:
nameserver 208.67.222.222 nameserver 208.67.220.220
Save and close the file. To test DNS configuration type any one of the following command:
$ host google.com $ dig google.com $ ping google.com $ nslookup your-domain.com
Output:

google.com has address 72.14.207.99
google.com has address 64.233.187.99
google.com has address 64.233.167.99
google.com mail is handled by 10 smtp4.google.com.
google.com mail is handled by 10 smtp1.google.com.
google.com mail is handled by 10 smtp2.google.com.
google.com mail is handled by 10 smtp3.google.com.

If you see valid output such as actual IP address or able to ping to remote server via hostname, it means that the dns is working for you. Also make sure you have valid default gateway setup, if you see the time out error.

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{ 14 comments… read them below or add one }

1 me December 19, 2007 at 9:01 pm

you’re easily sliding to the point where your tutorials will be as complex as ‘how to start your computer? press the power button!’

haha

2 Ash December 19, 2007 at 9:08 pm

Typo:
nslookup

3 Robert de Bock December 20, 2007 at 10:49 am

Ping is a tool to send ICMP echo requests to machines, not to check if resolving works. nslookup, dig and host can be used to check resolving, as you perfectly describe in this article.

4 musolff92 July 2, 2011 at 3:25 am: well that’s true, but it has to resolve the dns name before it can continue the ping. So ping works too.
Reply

5 user December 20, 2007 at 4:33 pm

> http://www.google.com
Server: 208.67.222.222
Address: 208.67.222.222#53

Non-authoritative answer:
http://www.google.com canonical name = google.navigation.opendns.com.
Name: google.navigation.opendns.com
Address: 208.67.219.230
Name: google.navigation.opendns.com
Address: 208.67.219.231

6 Phil January 22, 2008 at 1:44 pm

Using nslookup you can query different name servers.

nslookup http://www.google.com XXX.XXX.XXX.XXX

where XXX.XXX.XXX.XXX is the ip adress or name of the name server you are trying to query.

Doing :
nslookup http://www.google.com localhost
will query your local dns server if you have one.

7 Sajain Geevar July 8, 2008 at 8:33 am

How can I specify something like for site say ‘www.mysite.com’ go to this ip say ’192.168.1.2′?

8 vivek July 8, 2008 at 7:17 pm

You need to set named or bind9 software to point to specific IP.

9 FM September 20, 2008 at 4:51 am

I WANT THE COMMAND ON LINUX TO CREATE DNS & DHCP SERVER.

10 Ashis September 4, 2011 at 2:14 pm

i m very much crazy abt Linux

11 FuzzyGhost June 19, 2012 at 2:53 pm

How does one set this permanently though? /etc/resolv.conf will erase changes upon reboot/shutdown.

12 Andy October 8, 2012 at 6:20 pm: From resolv.conf:
# No nameservers found; try putting DNS servers into your
# ifcfg files in /etc/sysconfig/network-scripts like so:
#
# DNS1=xxx.xxx.xxx.xxx
# DNS2=xxx.xxx.xxx.xxx
# DOMAIN=lab.foo.com bar.foo.com
Reply

13 Dr Chaos October 4, 2012 at 1:42 am