if this is a vps then you can check with your provider to set dns servers for you.
Add "PEERDNS=no". This option will prevent /etc/resolv.conf from being modified
file /etc/sysconfig/network-scripts/ifcfg-eth0 (or other your server has), example
PEERDNS=no
or add tis in the same file
DNS1=8.8.8.8
DNS2=8.8.4.4