unboud stops multiple times per day, due to part of Router Advertisement expired

George Thessalonikefs george at nlnetlabs.nl
Mon May 17 13:25:15 UTC 2021


Hi Peter,

Since you mentioned something about pfsense, this could also be a 
culprit for sending unbound a HUP signal (the second one).

Unbound does not explicitly log that it receives a HUP signal. Instead 
you will see unbound reloading without previously receiving an 
unbound-control command.

I am afraid I cannot help you further because as I said unbound does not 
reload on its own. Maybe someone else that uses a similar setup could 
provide more information.

-- George

On 17/05/2021 15:17, Peter Russell via Unbound-users wrote:
> Thank you for your reply
> 
> I agree that it's probably the DHCP daemon that triggers unbound to restart,
> not directly, but because unbound detects a routing change.
> Since there is a syslog message from the daemon (dhcpcd[562]: eth0: part of
> Router Advertisement Expired), it is the probable cause for unbound to
> restart.
> 
> However (1) the message says part of the routing expired, shouldn't unbound
> ignore expired routes?
> 
> However (2) , as I mentioned before, unbound restarts twice, every time this
> happens.
> There is nothing I can find that would explain the second restart.
> So this looks like something unbound is doing, without any external event or
> command.
> 
> I very much doubt it is an unbound-control command, these are logged in the
> unbound log.
> Not sure if SIGHUB signals are logged...
> 
> -----Original Message-----
> From: Unbound-users [mailto:unbound-users-bounces at lists.nlnetlabs.nl] On
> Behalf Of George Thessalonikefs via Unbound-users
> Sent: Monday, 17 May, 2021 2:45 PM
> To: unbound-users at lists.nlnetlabs.nl
> Subject: Re: unboud stops multiple times per day, due to part of Router
> Advertisement expired
> 
> Hi Peter,
> 
> Unbound does not restart on its own.
> I suspect that the DCHP daemon (or something else on your system) instructs
> unbound to reload (either with SIGHUP or via unbound-control
> reload) when there is a DHCP update.
> 
> I would advise to look at the DHCP configuration for further
> troubleshooting.
> 
> Best regards,
> -- George
> 
> On 14/05/2021 19:30, Peter Russell via Unbound-users wrote:
>> Unbound 1.13.1, with ./configure --prefix=/usr --sysconfdir=/etc
>> --disable-static --enable-tfo-client --enable-tfo-server
>> --with-libevent --with-libhiredis --enable-cachedb
>> --with-pidfile=/run/unbound.pid
>>
>> The log shows, multiple times per day:
>>
>> May 14 06:15:26 unbound[790:0] info: service stopped (unbound 1.13.1).
>>
>> info: server stats for thread 0: 0 queries, 0 answers from cache, 0
>> recursions, 0 prefetch, 0 rejected by ip ratelimiting
>>
>> info: server stats for thread 0: requestlist max 0 avg 0 exceeded 0
>> jostled 0
>>
>> info: mesh has 1 recursion states (0 with reply, 1 detached), 0
>> waiting replies, 0 recursion replies sent, 0 replies dropped, 0 states
>> jostled out
>>
>> info: server stats for thread 1: 0 queries, 0 answers from cache, 0
>> recursions, 0 prefetch, 0 rejected by ip ratelimiting
>>
>> info: server stats for thread 1: requestlist max 0 avg 0 exceeded 0
>> jostled 0
>>
>> info: mesh has 0 recursion states (0 with reply, 0 detached), 0
>> waiting replies, 0 recursion replies sent, 0 replies dropped, 0 states
>> jostled out
>>
>> info: server stats for thread 2: 0 queries, 0 answers from cache, 0
>> recursions, 0 prefetch, 0 rejected by ip ratelimiting
>>
>> info: server stats for thread 2: requestlist max 0 avg 0 exceeded 0
>> jostled 0
>>
>> info: mesh has 0 recursion states (0 with reply, 0 detached), 0
>> waiting replies, 0 recursion replies sent, 0 replies dropped, 0 states
>> jostled out
>>
>> info: server stats for thread 3: 0 queries, 0 answers from cache, 0
>> recursions, 0 prefetch, 0 rejected by ip ratelimiting
>>
>> info: server stats for thread 3: requestlist max 0 avg 0 exceeded 0
>> jostled 0
>>
>> info: mesh has 0 recursion states (0 with reply, 0 detached), 0
>> waiting replies, 0 recursion replies sent, 0 replies dropped, 0 states
>> jostled out
>>
>> notice: Restart of unbound 1.13.1.
>>
>> unbound than almost always immediately stops a second time:
>>
>> May 14 06:15:27 unbound[790:0] info: service stopped (unbound 1.13.1).
>>
>> verbosity 1, which, according to the manual, should display all errors.
>>
>> I've narrowed it down to a specific matching syslog entry:
>>
>> The syslog entries:
>>
>> May 14 06:15:26 raspberrypi dhcpcd[562]: eth0: part of Router
>> Advertisement expired
>>
>> May 14 07:09:04 raspberrypi dhcpcd[562]: eth0: Router Advertisement
>> from fe80::20e:c4ff:fecf:f3cf
>>
>> May 14 07:09:04 raspberrypi dhcpcd[562]: eth0: Router Advertisement
>> from fe80::20e:c4ff:fecf:f3cf
>>
>> May 14 14:53:25 raspberrypi dhcpcd[562]: eth0: part of Router
>> Advertisement expired
>>
>> The unbound entries:
>>
>> May 14 06:15:26 unbound[790:0] info: service stopped (unbound 1.13.1).
>>
>> May 14 06:15:27 unbound[790:0] info: service stopped (unbound 1.13.1).
>>
>> May 14 14:53:25 unbound[790:0] info: service stopped (unbound 1.13.1).
>>
>> May 14 14:53:29 unbound[790:0] info: service stopped (unbound 1.13.1).
>>
>> Notice the time match, part of Router Advertisement expired apparently
>> triggers an unbound restart
>>
>> the IPv4 address is served by a static (MAC based) entry, thus never
>> changes.
>>
>> the IPv6 address is served by a pfsense firewall (configured with
>> 'track interface'), never changes, unless ISP resets... (didn't happen
> today).
>>
>> There is really nothing I can do about the IP address assignment.
>>
>> Not sure how to proceed from here, I don't understand why an expired
>> route causes unbound to restart
>>
> 


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