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Could anybody please, enlighten me on the following messages in my logs for Bind:

sync 127.in-addr.arpa(unknown command): 2 Time(s)
sync domain.com(unknown command): 2 Time(s)

It's neither an error nor a warning. It's all up and running OK and I see no problems anywhere. How do I fix it what is it all about? I cannot seem to google anything on it. Many thanks in advance!

Dennis
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1 Answers1

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Maybe someone or something is issuing commands like:

rndc sync 127.in-addr.arpa
rndc sync domain.com

but the version of BIND you're using is too old to support that command?

When you're using dynamic DNS updates, rndc sync will update the actual DNS data file, so that the zone's journal file becomes unnecessary and can be deleted. On older BIND versions, I think you had to use rndc freeze followed by rndc thaw to get the same effect.

telcoM
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  • Thank you for replying, teloM. Appreciate. Is that actually the output when Bind is restarted? Is it fixable somehow? Where do I check for it in Bind 9.8? – Dennis Aug 24 '19 at 10:59
  • As you might know, `rndc` is the administrative tool for BIND, that can be used to send commands to a running BIND instance. Something, perhaps a DNS zone management tool, or a cron job, seems to be running those commands. [According to BIND 9.8 Administrator Reference Manual (ARM)](https://downloads.isc.org/isc/bind9/9.8.0/doc/arm/Bv9ARM.pdf) pages 10-12, the `rndc` command of BIND 9.8 does not yet support the `sync` subcommand, and neither does [version 9.8.8](https://downloads.isc.org/isc/bind9/9.8.8/doc/arm/man.rndc.html) which seems to be the last of the 9.8.x series. – telcoM Aug 24 '19 at 15:05
  • If you don't know what is issuing those commands, you might try something like `grep -r "rndc sync" /etc /root /usr/local /opt /var/spool` to find out. – telcoM Aug 24 '19 at 15:08