When you create Domain Name System (DNS) zone data, your server will be able to resolve queries to that zone.
Root servers are critical to the function of a DNS server that is directly connected to the Internet or a large intranet. DNS servers must use root servers to answer queries about hosts other than those that are contained in their own domain files.
To reach out for more information, a DNS server has to know where to look. On the Internet, the first place that a DNS server looks is the root servers. The root servers direct a DNS server toward other servers in the hierarchy until an answer is found, or it is determined that there is no answer.
You should use Internet root servers only if you have an Internet connection and you want to resolve names on the Internet if they are not resolved on your DNS server. A default list of Internet root server is supplied in iSeries Navigator. The list is current when iSeries Navigator is released. You can verify that the default list is current by comparing it to the list on the InterNIC site. Update your configuration's root server list to keep it current.
The top-level root server's addresses change from time to time, and it is the DNS administrator's responsibility to keep them current. InterNIC maintains a current list of Internet root server addresses. To obtain a current list of Internet root servers, follow these steps:
A DNS server behind a firewall might have no root servers defined. In this case, the DNS server can resolve queries only from entries that exist in its own primary domain database files, or its cache. It might forward off-site queries to the firewall DNS. In this case, the firewall DNS server acts as a forwarder.
If your DNS server is part of a large intranet, you might have internal root servers. If your DNS server will not be accessing the Internet, you do not need to load the default Internet servers. However, you should add your internal root servers so that your DNS server can resolve internal addresses outside of its domain.