Which command can be used to flush DNS cache in Ubuntu?
2 Answers
By default in Ubuntu is no caching DNS query.
If you use remote DNS server, then you have no chance to update their cache.
If you install local server. BIND:
rndc flush
nscd:
service nscd reload
dnsmasq:
/etc/init.d/dnsmasq restart
In my ubuntu 11.04 , I ran this:/etc/init.d/dns-clean
to clean dns
it's content is as follow:
#! /bin/sh
# $Id: dns-clean,v 1.1.1.1 2004/05/07 03:12:59 john Exp $
# dns-clean by John Hasler 1999-2003
# Any possessor of a copy of this program may treat it as if it
# were in the public domain. I waive all rights.
# This script should be run at bootup to clean up any mess left by 0dns-up.
# It should be run before ppp is started.
# It should never be run while ppp is up.
### BEGIN INIT INFO
# Provides: dns-clean
# Required-Start: $local_fs $remote_fs gdm
# Required-Stop: $local_fs
# Default-Start: 1 2 3 4 5
# Default-Stop:
# Short-Description: Cleans up any mess left by 0dns-up
# Description: 0dns-up often leaves behind some cruft. This Script is meant
# to clean up any such mess.
### END INIT INFO
PATH=/sbin:/bin:/usr/sbin:/usr/bin
test -f /usr/sbin/pppconfig || exit 0
# We might have a tmpfs /var/run.
mkdir /var/run/pppconfig >/dev/null 2>&1 || true
test -f /etc/ppp/ip-down.d/0dns-down || exit 0
. /lib/lsb/init-functions
. /etc/default/rcS
case "$1" in
start)
[ "$VERBOSE" != no ] && log_begin_msg "Restoring resolver state..."
/etc/ppp/ip-down.d/0dns-down "0dns-clean"
[ "$VERBOSE" != no ] && log_end_msg $?
;;
stop|restart|force-reload)
;;
*)
;;
esac
exit 0