Why use root hints in dns

Did you find the page informational and useful? Share it using one of your favorite social sites. Client-Side Development. Server-Side Development. IT Tools. Your email address will not be published. Root Hints The root hints file named. This file allows a DNS server to resolve domain names that are not in its authoritative and cached data.

There are 13 root nameservers a. All queries from nameservers to the root nameservers are iterative , thereby allowing the root nameservers to refer the client nameservers to other nameservers for domain name resolution. All other queries will go follow the conventional path for resolving names that is, up to the authoritative DNS server for the root top-level domain, if necessary.

The server will also examine its cache of resolved queries and send the data back to the client that sent the query. If the DNS server is configured to forward for the domain name designated in the query, the query is forwarded to the IP address of the DNS forwarder that is associated with that domain name.

If the DNS server has no forwarder listed for the name designated in the query, it attempts to resolve the query using standard recursion. You can use conditional forwarders to enhance and improve upon both internal and external name resolution.

Remember that with a stub zone, certain records exist on the DNS server hosting the stub zone, whereas a conditional forwarder is used to forward DNS resolutions to specific DNS servers based on domain name.

In planning your DNS namespace, you will encounter situations in which you might need to use any of the types of forwarders that we discussed. The way you configure your forwarders within your environment will affect how well queries are answered.

If your forwarding scheme is poorly designed, it will affect your ability to properly direct and resolve these queries. For this reason, you need to consider some issues prior to implementing forwarders into your environment:.

Keep in mind that every time a DNS server attempts to process a query, it first attempts to resolve it locally, and then forwards it sequentially through its list of known DNS forwarders.

This creates additional overhead by using system resources to complete the query request. This practice simply creates a bottleneck within your environment. To keep a DNS forwarder from becoming a bottleneck—and a single point of failure—consider creating more than one DNS forwarder and load-balance your forwarding traffic. In other words, if you are configuring your internal DNS servers to forward requests for www.