Configure Linux as DNS Client [resolv.conf]

Local name resolution in linux is done using /etc/hosts file. To configure linux as a DNS client you need to modify /etc/resolv.conf file.

/etc/resolv.conf

This file contains the ip addresses of name server i.e. DNS server. To configure linux as a DNS client open /etc/resolv.conf in any text editor vi, vim, nano, gedit or anything you love. vi or vim is the most loved one but I personally like nano. Its easy to use and have lots of features.

Add your nameservers as follows.

search myisp.com

nameserver 8.8.8.8

nameserver 8.8.4.4

nameserver 208.67.222.222

search myisp.com: The search list is normally determined from the local domain name; by default, it contains only the local domain name. So when you type nslookup www, it will be matched to www.myisp.com

nameserver 8.8.8.8: Point out to your own nameserver or to ISP's name server. Max 3 name servers may be listed.

Test the setup:

Now lets test the setup. You can use dig and nslookup to test if the name resolutions is working properly.

# dig www.googlinux.com

; <<>> DiG 9.7.0-P1 <<>> www.googlinux.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 5151

;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:

;www.googlinux.com. IN A

;; ANSWER SECTION:

www.googlinux.com. 2472 IN A 97.74.144.149

;; Query time: 88 msec

;; SERVER: 8.8.8.8#53(8.8.8.8)

;; WHEN: Tue Jan  3 22:59:45 2012

;; MSG SIZE  rcvd: 51

# nslookup www.googlinux.com

Server: 8.8.8.8

Address: 8.8.8.8#53

Non-authoritative answer:

Name: www.googlinux.com

Address: 97.74.144.149