Linux system has a parse the file/etc/resolt. Conf, nameserver configuration parameters specify the DNS server IP address, usually set up two nameserver plays the main role, but I want to accomplish in two nameserver at the same time, if the first nameserver specified server without domain name analytic results can cycle to the next nameserver the specified domain name server IP address, how to implement? Or are there other ways to implement multiple DNS server method for loop through DNS records? Rather than the state of the main case, teachers please comment. Thanks