Ich habe heute durch Zufall entdeckt, dass sich im Log eine falsche locale Domain findet:
rapi.fritz.box.fritz.box
Kann mir jemand verraten wie es passieren kann, dass ein zusätzliches "fritz.box" an die korrekte Domain angehängt wird ?
On the "rapi" box:
hostname -s; hostname -f;
hostname -s; hostname -f;
rapi
rapi
It is not that easy :pensive
host rapi
rapi.fritz.box has address 192.168xxxx
rapi.fritz.box has IPv6 address 2003:e7:13c8:xxxxxxxxx
Alles scheint ok zu sein.
If its in the Pi-Hole logs, who is making those queries would be my first question:
grep -e '^.*query.*rapi.fritz.box.fritz.box.*$' /var/log/pihole.log | awk '{print $8}' | sort | uniq -c | sort -n -r | head -10
Weird thing is, "rapi.fritz.box.fritz.box" is already setup publicly to resolve to 127.0.53.53 (localhost interface) as can be seen from below resolving via Google DNS(8.8.8.8):
$ host rapi.fritz.box.fritz.box 8.8.8.8
Using domain server:
Name: 8.8.8.8
Address: 8.8.8.8#53
Aliases:
rapi.fritz.box.fritz.box has address 127.0.53.53
rapi.fritz.box.fritz.box mail is handled by 10 your-dns-needs-immediate-attention.box.
Sounds like this hostname is setup by Fritz for some internal process that needs the record.
But i have no experience with FritzBox so maybe someone else can enlighten.
@deHakkelaar It is my MBA laptop which does these queries (terminal sessions). It runs an official macOS beta, maybe that's the reason for these issues - but I do not believe it. I got a lot of trouble with unresolved local domain names. I have no idea why dnsmasq forwards correct local domain names to e.g. 208.67.220.220 and not to my fritzbox, which is configured as upstream DNS for the local net.
Apr 1 09:05:09 dnsmasq[1532]: query[AAAA] data.fritz.box from 192.168.xxxxxx
Apr 1 09:05:09 dnsmasq[1532]: forwarded data.fritz.box to 208.67.220.220
The result of these wrong queries is always
data.fritz.box has address 127.0.53.53
data.fritz.box mail is handled by 10 your-dns-needs-immediate-attention.box.
The weird thing is, that it works sometimes for a while before it stops working again - a couple of days ago I did a firmware update for the fritzbox - after that it worked, but only for a couple of hours.
It is so annoying I really wanna track down this problem 
P.S.: @Moderator könntest du bitte den Thread ins englische Forum verschieben, sind jetzt leider ins Englische abgerutscht 
We'll keep it here, it's more fun that way! 
@deHakkelaar Are you aware you're posting in English in the German subforum?
Jawohl aber mein Deutscher schrift ist nicht sehr gut.
No fun for mich
Hort sich an als seie die Fritzbox ausgerichted zum forwarden von diesem Fritzbox spezifiek namen fur ein ziel.
Was das ziel ist weis ich nicht.
Aber dies ist nicht wirklich Pi-Hole relatierd.
Keiner falscher namen jedoch richticher namen fur die wirkung von Fritzbox.
Ohw ps:
$ whois 208.67.220.220
NetName: OPENDNS-NET-1
Ref: https://whois.arin.net/rest/net/NET-208-67-216-0-1The Fritzbox (router/(V)DSL modem) is the DNS server for my LAN, it assigns the local IP addresses and resolves the local domain names.
It is, because dnsmasq/pihole forwards local domain names to the internet DNS server (OpenDNS), but it should forward these queries to my Fritzbox. Obviously this does not work, but I have no idea why.
I am afraid it has something to do with the IPv6 configuration of my Fritzbox. I have have disabled IPv6 now and i will see if it helps.
Have you checked Pi-Hole "Upstream DNS Servers" settings ?
You can enter a "Custom" IP address like for example your Fritzbox.
But make sure Fritzbox is the only DNS server set as upstream DNS resolver or expect troubles again!
*I tried in Deutsch but was toooo hard
I feel stupid 
- the Fritzbox is configured as first Upstream DNS server, BUT I have setup the second Upstream DNS server too - shame on me. Thank you @deHakkelaar for the push in the right direction.
Good job!
I added this bit at bottom of below post that I replied on.
(yes again in plain stupid English