Bash Clear DNS Cache

last updated October 26, 2009 in CentOS, Debian / Ubuntu, FAQ, Linux, Mac OS X, RedHat and Friends, Ubuntu Linux, UNIX

How do I clear DNS cache using BASH shell prompt under UNIX like operating systems?

DNS queries are cached to speed up DNS data access.

Linux – NSCD

Nscd caches libc-issued requests to the Name Service. If retrieving NSS data is fairly expensive, nscd is able to speed up consecutive access to the same data dramatically and increase overall system performance. Type the following command under Linux operating systems. Open a terminal and enter:
/etc/init.d/nscd restart
OR
sudo /etc/init.d/nscd restart

MAC OS X

Open a terminal and type the following command under OS X Leopard (v10.5):
dscacheutil -flushcache
Note if you are Mac OS X Tiger (v10.4) user, enter:
lookupd -flushcache

Posted by: Vivek Gite

The author is the creator of nixCraft and a seasoned sysadmin, DevOps engineer, and a trainer for the Linux operating system/Unix shell scripting. Get the latest tutorials on SysAdmin, Linux/Unix and open source topics via RSS/XML feed or weekly email newsletter.

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Tagged as: /etc/init.d/nscd, access linux, BASH Shell, caches, data access, dscacheutil -flushcache, linux operating systems, lookupd -flushcache, Mac OS X, mac os x tiger, nss data, os x leopard, os x tiger, performance type, system performance, UNIX