Syslog: notice unbound[]: [6432:0] notice: sendto failed: Permission denied

I have found plenty of rows in Turris1.0 messages log file:

2019-10-08 22:23:45 notice unbound[]: [6432:0] notice: remote address is 2001:503:83eb::30 port 53
2019-10-08 22:23:48 notice unbound[]: [6432:0] notice: sendto failed: Permission denied
2019-10-08 22:23:48 notice unbound[]: [6432:0] notice: remote address is 2001:500:200::b port 53
2019-10-08 22:23:48 notice unbound[]: [6432:0] notice: sendto failed: Permission denied
2019-10-08 22:23:48 notice unbound[]: [6432:0] notice: remote address is 2001:503:c27::2:30 port 53

There is no longer working link to a solution, can anyone share a valid link to resolve the issue? The message is not any harm, but as soon as one need to find something in the log file, having messages flooded by this message make things tedious.

Thanks for any solution hint. IPv6 is disabled on WAN port.

Thanks ales

Suppose 2001:503:83eb::30 is your ISP’s DNS resolver and not set manually by you.

Afaik the resolver settings are not dynamically checking/applying upstream ipv4/6 connectivity but assuming both active.

According to source code the setting net_ipv6 in /etc/config/resolver translates to unbound’s setting do-ip6

Enable or disable whether ip6 queries are answered or issued.
Default is yes. If disabled, queries are not answered on IPv6,
and queries are not sent on IPv6 to the internet nameservers.
With this option you can disable the ipv6 transport for sending
DNS traffic, it does not impact the contents of the DNS traffic,
which may have ip4 and ip6 addresses in it.


syslog-ng also provides filtering facilities.

Or utilizing unbound setting use-syslog

Sets unbound to send log messages to the syslogd, using sys- log(3). The log facility LOG_DAEMON is used, with identity “unbound”. The logfile setting is overridden when use-syslog is turned on. The default is to log to syslog.

and/or logfile

If “” is given, logging goes to stderr, or nowhere once daemo-
nized. The logfile is appended to, in the following format:
[seconds since 1970] unbound[pid:tid]: type: message.
If this option is given, the use-syslog is option is set to
“no”. The logfile is reopened (for append) when the config file
is reread, on SIGHUP.


Also there is https://gitlab.labs.nic.cz/turris/turris-os-packages/issues/463

Thanks a lot!
Changing net_ipv6 perfectly works. This is fine in my case, since IPv6 did not worked for me properly, therefre till ISP will reslove it, your solution if perfect for my situation.
Aleš