I was going to write a script to automatically update the root hints files on my Bind servers. Then I found this excellent script – you will need to modify it to suit your own environment:

#!/bin/sh
#
# Update the nameserver cache information file once per month.
# This is run automatically by a cron entry.
#
# Original by Al Longyear
# Updated for BIND 8 by Nicolai Langfeldt
# Miscelanious error-conditions reported by David A. Ranch
# Ping test suggested by Martin Foster
# named up-test suggested by Erik Bryer.
#
(
echo “To: root ”
echo “From: system ”

# Is named up? Check the status of named.
case `rndc status 2>&1` in
*refused*)
echo “named is DOWN. root.hints was NOT updated”
echo
exit 0
;;
esac

PATH=/sbin:/usr/sbin:/bin:/usr/bin:
export PATH
# NOTE: /var/named/master must be writable only by trusted users or this script
# will cause root compromise/denial of service opportunities.
cd /var/named/master 2>/dev/null || {
echo “Subject: Cannot cd to /var/named/master, error $?”
echo
echo “The subject says it all”
exit 1
}

# Are we online? Ping a server at your ISP
case `ping -qnc 1 somehost.net 2>&1` in
*’100% packet loss’*)
echo “Subject: db.cache NOT updated. The network is DOWN.”
echo
echo “The subject says it all”
exit 1
;;
esac

dig @e.root-servers.net . ns >db.cache.new 2> errors

case `cat db.cache.new` in
*NOERROR*)
# It worked
:;;
*)
echo “Subject: The db.cache file update has FAILED.”
echo
echo “The db.cache update has failed”
echo “This is the dig output reported:”
echo
cat db.cache.new errors
exit 1
;;
esac

echo “Subject: The db.cache file has been updated”
echo
echo “The db.cache file has been updated to contain the following
information:”
echo
cat db.cache.new

chown named.named db.cache.new
chmod 444 db.cache.new
rm -f db.cache.old errors
mv db.cache db.cache.old
mv db.cache.new db.cache
rndc reload
echo
echo “The nameserver has been restarted to ensure that the update is complete.”
echo “The previous root.hints file is now called
/var/named/master/db.cache.old.”
) 2>&1 | /usr/lib/sendmail -t

exit 0