Download root hint file.

If you found log entries similar to the messages listed below then your current root hint file is out of date.

Dec 21 09:12:02 srv named: checkhints: ( missing from hints
Dec 21 09:12:02 srv named: checkhints: ( extra record in hints

You can update it directly from the InterNIC site.

$ ftp -a
Connected to
220 Internic FTP Server.
331 Please specify the password.
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.
200 Switching to Binary mode.
250 Directory successfully changed.
Retrieving domain/named.root
local: named.root remote: named.root
150 Opening BINARY mode data connection for named.root (2994 bytes).
100% |******************************************************|  2994       00:00
226 File send OK.
2994 bytes received in 0.07 seconds (41.52 KB/s)
221 Goodbye.