Root Server File named. Root

In the main configuration file/etc/named. conf, a root domain is defined. The zone file is the named. root file under the/var/named directory. It is a very important file that contains the name and IP address of the Internet root server. When the BIND receives a query request from the client, if it cannot be explained locally or the corresponding data cannot be found in the cache, it will perform a step-by-step query through the root server.

For example, when the server receives a query request from the DNS client to query a domain name www.example.com that is not in the current domain, if no data exists in the cache, the DNS server sends the request to the named. the Internet root server requests listed in the root file, and then the root server sends the query to the responsible domain. com authorization name server, domain. the com authorization name server then sends the request to the authorization name server in charge of domain example.com for query, and then returns the result to the client.

Because the address of the Internet root server often changes, named. root should also be updated accordingly. The latest root server list can be downloaded from ftp://ftp.rs.internic.net/domain/. the file name is also named.rootand contains the latest data provided by InterNIC. In addition, you can use the dig Command provided by bind to list the latest root server.