unbound flooding syslog with 'sendto failed: Cannot assign requested address'

unbound at henk.geekmail.org unbound at henk.geekmail.org
Thu Oct 22 10:44:46 UTC 2015

Hi Wouter

On Fri, 16 Oct 2015 13:28:12 +0200
"W.C.A. Wijngaards via Unbound-users" <unbound-users at unbound.net> wrote:

> > IPv6 is disabled on this system, it has neither an IPv6 address on
> > any interface nor a route set.  
> Unbound does not know IPv6 is disabled, so it tries.  The failure is
> harmless (apart from annoying with a log message in this unbound
> version you are using).  You could do-ip6: no in unbound.conf to make
> the log messages go away.  Or upgrade to a newer version.

Ah, that explains it, and probably solves it, thanks.

> Well if you disable IPv6 and then ::1 does not exist, then you'd also
> have to disable ::1 for unbound, i.e. do-ip6: no.  In any case, you
> could either disable ipv6 for unbound, or configure it with
> as the interface to bind to with interface: and control-interface:.

Seems I only did that for interface: but missed control-interface:
because it did not show up at all in the config …

> In later versions of unbound this error may also go away, but there
> have been many releases in the meantime, so I am not sure.  (it would
> detect ipv6 is disabled and not fail and not bother you about it).


> Apart from all of the above, would you enable IPv6?  This is not to
> fix the issue you have with your Unbound configuration, but because
> IPv6 is necessary for connecting future internet users?

Generally yes. I have been using IPv6 since 2009 both on my server and
at home. Some time this year I got a new uplink at home and with that a
new router from mikrotik. I ran into some kind of bug with
autoconfiguration though which might be the issue explained in [0]. I
didn’t have the time to figure that out exactly at the time and just
disabled IPv6 altogether. I reenabled it now after upgrading to a new
routeros firmware and will see how it turns out.
I appreciate you asking the question like you did! IPv6 needs more
proponents and implementors. Things have been going way too slow!

[0]: http://forum.mikrotik.com/viewtopic.php?t=77404

Thank you very much and best regards


A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
A: Top-posting.
Q: What is the most annoying thing in e-mail?
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