DHCP leases slow to register in Unbound DNS

Started by FullyBorked, October 25, 2021, 04:05:18 PM

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October 25, 2021, 04:05:18 PM
Currently I'm experiencing an issue where new devices that use DHCP aren't able to be resolved in DNS for some time.  I have "Register DHCP leases" and "Register DHCP static mappings" both enabled in Unbound General config.   I'm not sure what eventually triggers them to be registered in DNS.  Would assume this should be near instant, but maybe it requires some process to run in Unbound before they are available? Is there a way to increase this frequency?
October 25, 2021, 10:02:02 PM #1
QuoteIs there a way to increase this frequency?
no afaik (its 1 sec for new leases and 1 min for expired)
there should be another reason imho (negative caching or some)
October 25, 2021, 10:05:00 PM #2
Quote from: Fright on October 25, 2021, 10:02:02 PM
QuoteIs there a way to increase this frequency?
no afaik (its 1 sec for new leases and 1 min for expired)
there should be another reason imho (negative caching or some)

Hmm, yea I had a new device this morning that didn't resolve even after hours of waiting.  Finally restarted unbound and it resolved instantly.  Not sure where to even start to troubleshoot. 
October 25, 2021, 10:34:11 PM #3
Quotedidn't resolve even after hours of waiting. Finally restarted unbound and it resolved instantly
it looks like dhcpd monitoring process worked fine and the .conf file wrote ok. but something went wrong when transferring data to unbound via unbound-control.
Any clues in the unbound log before restarting?
October 25, 2021, 10:41:29 PM #4
Quote from: Fright on October 25, 2021, 10:34:11 PM
Quotedidn't resolve even after hours of waiting. Finally restarted unbound and it resolved instantly
it looks like dhcpd monitoring process worked fine and the .conf file wrote ok. but something went wrong when transferring data to unbound via unbound-control.
Any clues in the unbound log before restarting?

Nothing useful unfortunately.  As far as unbound is concerned it at least "thinks" it's operating properly. 
October 29, 2021, 05:31:01 PM #5
sorry, not enough info for guesses
October 29, 2021, 05:34:54 PM #6
Quote from: Fright on October 29, 2021, 05:31:01 PM
sorry, not enough info for guesses

Sorry, yea there isn't much.  I only have evidence for the symptoms.  I'm not getting anything to guide me for the actual cause.  No error messages on the DHCP or the DNS side of things.  Only way to fix it is to restart the services which happens nightly via cron when updating blacklists.  So the longest it's broke is <24 hours. 
October 29, 2021, 05:38:20 PM #7
still a guess, unbound statistics are displayed (Services: Unbound DNS: Statistics)?
October 29, 2021, 05:45:30 PM #8
Quote from: Fright on October 29, 2021, 05:38:20 PM
still a guess, unbound statistics are displayed (Services: Unbound DNS: Statistics)?

Yes they are displayed without issue.
October 30, 2021, 10:17:20 AM #9
hm. so unbound-control itself works
if you really want to figure it out, i can try to add a little debugging to the monitoring script and we will try to understand at what stage something is going wrong.
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