The Root Name Server Cache

Downloading a new Root Name Server Cache for your BIND Linux DNS server is easy and should take less than a minute from the command line of your Linux server. The root cache db is a small text file that provides the IP addresses and names of the parent DNS servers that is an important requirement for recursive name servers. Without a current root cache db your name server may not be able to look up all of the parent name servers and this may impede its functionality.

The root cache db goes by several different names depending on your Linux distribution and how BIND was installed. On our Slackware Linux server the root cache is called named.hint. On the Ubuntu Linux server it is called db.root. It may also be called named.root, named.cache, root.hint or root.zone amongst many others. Find out what your root cache is called by reading your /etc/named.conf, the lines in named.conf referring to your root cache will appear something like the ones below this paragraph. Make a note of what its called.

zone "." IN { type hint; ; file "named.hint"; };

The best place to download a fresh root cache is directly from the Internic ftp server. Internic is operated by ICANN, the Internet Corporation for Assigned Names and Numbers who are responisble for managing and coordinating the domain name system. The process is very straightforward, ftp anonymously to ftp.rs.internic.net, change to the domain folder and get named.root. Once you have named.root on your Linux server you can rename it to suit your configuration.

# ftp ftp.rs.internic.net Connected to ftp.rs.internic.net. 220-********************************************************** 220-********************************************************** 220-***** InterNIC Public FTP Server ************************* 220-********************************************************** 220-***** Login with username "anonymous" ******************** 220-***** You may change directories to the following: ******* 220-********************************************************** 220-******* domain - Root Domain Zone Files ****************** 220-********************************************************** 220-***** Unauthorized access to this system may ************* 220-***** result in criminal prosecution. ******************** 220-********************************************************** 220-***** All sessions established with this server are ****** 220-***** monitored and logged. Disconnect now if you do ***** 220-***** not consent to having your actions monitored ******* 220-***** and logged. **************************************** 220-********************************************************** 220-********************************************************** 220 Name (ftp.rs.internic.net:root): anonymous 331 Please specify the password. Password:Press Enter 230 Login successful. Remote system type is UNIX. Using binary mode to transfer files. ftp> cd domain 250 Directory successfully changed. ftp> ls 200 PORT command successful. Consider using PASV. 150 Here comes the directory listing. -rw-r--r-- 1 ftp ftp 607 Nov 01 19:31 INTERNIC_ROOT_ZONE.signatures -rw-r--r-- 1 ftp ftp 843 Nov 01 19:31 INTERNIC_ROOT_ZONE.signatures.asc -rw-r--r-- 1 ftp ftp 694 Nov 01 19:15 arpa.zone.gz -rw-r--r-- 1 ftp ftp 33 Nov 01 19:14 arpa.zone.gz.md5 -rw-r--r-- 1 ftp ftp 65 Nov 01 19:15 arpa.zone.gz.sig -rw-r--r-- 1 ftp ftp 2938 Jul 09 14:55 db.cache -rw-r--r-- 1 ftp ftp 48 Jul 09 14:55 db.cache.md5 -rw-r--r-- 1 ftp ftp 1326 Jul 09 14:55 db.cache.sig -rw-r--r-- 1 ftp ftp 2941 Jul 09 14:55 named.cache -rw-r--r-- 1 ftp ftp 51 Jul 09 14:55 named.cache.md5 -rw-r--r-- 1 ftp ftp 1322 Jul 09 14:55 named.cache.sig -rw-r--r-- 1 ftp ftp 2940 Jul 09 14:55 named.root -rw-r--r-- 1 ftp ftp 50 Jul 09 14:56 named.root.md5 -rw-r--r-- 1 ftp ftp 1330 Jul 09 14:56 named.root.sig -rw-r--r-- 1 ftp ftp 83145 Nov 01 19:32 root.zone -rw-r--r-- 1 ftp ftp 21228 Nov 01 19:33 root.zone.gz -rw-r--r-- 1 ftp ftp 33 Nov 01 19:31 root.zone.gz.md5 -rw-r--r-- 1 ftp ftp 65 Nov 01 19:31 root.zone.gz.sig -rw-r--r-- 1 ftp ftp 33 Nov 01 19:32 root.zone.md5 -rw-r--r-- 1 ftp ftp 65 Nov 01 19:33 root.zone.sig 226 Directory send OK. ftp> get named.cache local: named.cache remote: named.cache 200 PORT command successful. Consider using PASV. 150 Opening BINARY mode data connection for named.cache (2941 bytes). 226 File send OK. 2941 bytes received in 0.00444 secs (6.5e+02 Kbytes/sec) ftp> quit 221 Goodbye. # cp named.cache named.hint