The commands listed belows are some that we use often, but many more exist. Check the man pages and documentation for more details and information.

dig.  The dig command utility domain information groper can be used to update your db.cache file by telling your server where the servers for the root zone are. When the server knows about the location of these zones, it queries a new db.cache from it. The root name servers do not change very often, but they do change. A good practice is to update your db.cache file every month or two.

Use the following command to query a new db.cache file for your DNS Server:

 [root@deep] /# dig @.aroot-servers.net . ns > db.cache
 

Copy the db.cache file to /var/named/ after retrieving it.

 [root@deep] /# cp db.cache /var/named/
 

Where @a.root-servers.net is the address of the root server for querying the new db.cache file and db.cache file is the name of your new db.cache file.

ndc.  The ndc command utility of ISC BIND/DNS allows the system administrator to control interactively via a terminal the operation of a name server. Type ndc on your terminal and then help to see help on different command.

 [root@deep] /# ndc
 

 Type   help  -or-   /h   if you need help.
 ndc> help
 getpid
 status
 stop
 exec
 reload [zone] ...
 reconfig (just sees new/gone zones)
 dumpdb
 stats
 trace [level]
 notrace
 querylog
 qrylog
 help
 quit
 ndc> /e