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7. Održavanje

Samo neka radi.

Jednu stvar moraš činiti za održavanje nameda, osim da ih puštaš da rade. To je održavanje root.hints datoteke ažurnom. Najlakši način je korištenje diga. Prvo pokreni dig bez parametara, i dobit ćeš root.hints svog servera. Onda pitaj jedan od izlistanih korijenskih servera sa dig @rootserver. Vidjet ćeš da izlazni podaci jako sliče onima u root.hints datoteci. Sačuvaj ih u datoteku (dig @e.root-servers.net . ns > root.hints.new) i zamijeni staru root.hints datoteku s novom (root.hints.new, op.prev.).

Zapamti da treba restartati named nakon promjene cache datoteke.

Al Longyear mi je poslao ovu skriptu koja se može pokrenuti automatski da obnovi root.hints. Unesite je u crontab kako bi se pokretala jednom mjesečno i zaboravite na nju. Ova skripta pretpostavlja da imaš podešen i radeći e-mail, te da je alias `hostmaster' definiran. Moraš je hackirati da je uskladiš sa svojim postavkama. (sačuvati kao izvršnu datoteku /etc/cron.monthly/hints.new, op.prev.)


#!/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: hostmaster <hostmaster>"
 echo "From: system <root>"

 # Is named up? Check the status of named.
 case `ndc status 2>&1` in
    *'cannot connect to command channel'*)
        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 must be writable only by trusted users or this script 
 # will cause root compromise/denial of service opportunities.
 cd /var/named 2>/dev/null || {
    echo "Subject: Cannot cd to /var/named, error $?"
    echo
    echo "The subject says it all"
    exit 1
 }

 # Are we online?  Ping a server at your ISP
 case `ping -qnc 1 some.machine.net 2>&1` in
   *'100% packet loss'*)
        echo "Subject: root.hints NOT updated.  The network is DOWN."
        echo
        echo "The subject says it all"
        exit 1
        ;;
 esac

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

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

 echo "Subject: The root.hints file has been updated"
 echo
 echo "The root.hints file has been updated to contain the following   
information:"
 echo
 cat root.hints.new

 chown root.root root.hints.new
 chmod 444 root.hints.new
 rm -f root.hints.old errors
 mv root.hints root.hints.old
 mv root.hints.new root.hints
 ndc restart
 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/root.hints.old."
) 2>&1 | /usr/lib/sendmail -t
exit 0

Neki su možda vidjeli root.hints datoteku koja je dostupna FTP-om od InterNIC-a. Molim vas, nemojte koristiti FTP da obnovite root.hints, jer je gornja metoda puno bolja za mrežu, i InterNIC.


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