Many DNS query from my NAS

hi, i just install pihole ( on a raspberry pi0w for testing, my syno did not have docker ) , and i saw that my nas ( synology ds414 ) make many many dns query(s) , like 1700 by minutes

there is no destination address ( why ? ) , i want to black it to 127.0.0.1

sometimes , my network fail ( too many querys ? )
did you now where the syno make this dns querry , and how to block them ?

thank's

Please provide some lines from /var/log/pihole.log showing this query and the reply. Thanks.

hi ,

i didn't think to see logs ....

i have many items like this :

Feb  7 06:33:30 dnsmasq[10028]: query[ANY] . from 192.168.0.254
Feb  7 06:33:30 dnsmasq[10028]: forwarded . to 208.67.222.222
Feb  7 06:33:30 dnsmasq[10028]: forwarded . to 208.67.220.220
Feb  7 06:33:30 dnsmasq[10028]: query[ANY] . from 192.168.0.254

(192.168.0.254 is my synology )
208.67.22x.xxx is open DNS ( it's that i have configured in pihole )
about 20 request by minutes .... but why ?

this phenomen appears when i set my pihole on synoloygy/parameters/network/prefered dns server .
and it stop when i select another dns ( like my isp )

but how i can know witch program use this amount of dns querry ?

I don't think it stops, it's just that you can't see it since the DNS traffic is no longer going through Pi-Hole - it's going to the ISP.

Note that these are "ANY" queries, which are not looking for an IP address specifically.