Unbound error: SERVFAIL

I have many errors in the logs of unbound

unbound: [3090:0]	error: SERVFAIL <0.ipfire.pool.ntp.org. AAAA IN>: all the configured stub or fo rward servers failed, at zone . no server to query nameserver addresses not usab le have no nameserver names

what could be the cause ?

It means that unbound is having problems accessing the dns servers that you have defined.

When you say you have many errors can you quantify that? Sometimes there can be a short problem accessing DNS servers so you may get a few of those messages but it is clear then. My system runs at around 0 to 500 per week. If you have several thousand then there is an ongoing problem.

I am presuming that you have confirmed that your Internet connection is working.

What do you get on your DNS Servers WUI page. What is the wording in the Overall Status (green Working or red Broken) and if you press the Check DNS servers button what result do you get for each individual specified server.

If it is not a green OK then if you place your mouse pointer over the red wording and leave it there for a short while it will come up with a short message about the failure.


Thank you for the answer, there is a good deconexion to the server dns tls at times so this would be the cause