Multiple Domain Name System (DNS) Servers should be configured
in /etc/resolv.conf. This provides redundant name resolution services
in the event that a domain server crashes. To configure the system to contain
as least 2 DNS servers, add a corresponding nameserver
ip_address entry in /etc/resolv.conf for each DNS
server where ip_address is the IP address of a valid DNS server.
For example:
search example.com
nameserver 192.168.0.1
nameserver 192.168.0.2