nameserver ip_address
The nameserver entry is used to inform the DNS resolver daemon of the IP address of a DNS server. The /etc/resolv.conf configuration file may contain a maximum of three nameserver entries.
When the DNS resolver daemon processes a DNS request, the DNS server defined with the first nameserver entry is queried first. If the first DNS server does not reply, the DNS server defined with the second nameserver entry is queried, if such an entry exists. If the second server also does not reply, the process is repeated with the third name server, and so on. If the DNS server defined by the third nameserver also does not reply, you should repeat the DNS request with all DNS servers until the maximum number of retries (see the options entry on "options entry", attempts parameter) is reached.