BIND9 dynamic configuration sharing from a master

/dev/rob0 rob0 at gmx.co.uk
Mon Jan 26 19:25:37 UTC 2004


Is there any means within BIND itself to share configuration changes at
a master nameserver among slaves? The site I set up last week wants to
block a blacklist of domains in DNS. I've got that all rigged up on the
master, using an $INCLUDE in named.conf:
    $INCLUDE "/etc/named.blacklist";
and a simple null zone file which sets SOA, NS and A records to the
master, and then sets a similar "*" A record.

I know I can rig this up manually quite easily, but I just wondered if
there was a means to dynamically update a slave's configuration within
BIND's own capabilities.

#v+
  if \\! grep "$FEATURE" "$BIND_FEATURES" ; then
    echo "$FEATURE" >> "$BIND_WISHLIST"
  fi # to say it in sh ... :)
#v-

I think I *will* use named to signal the slave that an update is needed.
I'll make a "dnsupdateconf" A record pointing to the master's IP, and
set a TXT record with a timestamp of the last update. The TXT record
will be cached on disk at the slave and compared against the output of
"host -t TXT dnsupdateconf" in a cron job. If the TXT value changes, the
slave retrieves /etc/named.blacklist from the master and "rndc reload".

Has anyone else done something like this? Comments appreciated.
-- 
  /dev/rob0 - preferred_email=i$((28*28+28))@softhome.net
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