To Setup DNS

1)  /etc/resolv.conf

2)  /etc/nsswitch.conf
    passwd:     files
    group:      files
    hosts:      files dns   <--- "dns"  must be added.
    networks:   files
    .....

3)  /etc/defaultrouter     (IP of router)
    123.123.123.1

4)  /etc/defaultdomain     
    myhost.dswkim.org

5)  /etc/networks     (network name)
    .....
    kkk-net    123.123.123
    .....

6)  /etc/hosts          (hostname)
    127.0.0.1       localhost
    123.123.123.123 myhost myhost.dswkim.org