Windows 10 - DNS request timed out - Problem after updating to PI-HOLE V5.11.4 FTL V5.16.1 WEB INTERFACE V5.13

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1

Hey Everyone,

I have some strange behaviour.
Tuesday I updated my Pi-Hole to the latest Version (PI-HOLE V5.11.4 FTL V5.16.1 WEB INTERFACE V5.13)
(Note: to do so, I had to Upgrade the OS from Debian 9 to 10)

After this update, all Windows PCs refuse to resolve any hostname on my local Network.
Browsing the Web is working fine.
Also my other Devices (Linux Mint / LMDE 4 / Pi / etc.) don't have any issues.

I have tried some requests via PowerShell:

nslookup without DNS Server specification:

PS C:\Users\Cetheus\AppData\Roaming\eDEX-UI> nslookup fritz.box
DNS request timed out.
    timeout was 2 seconds.
Server:  UnKnown
Address:  fe80::84b9:25b8:ffb3:6dbb

DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Zeitüberschreitung bei Anforderung an UnKnown.

nslookup against Pi-Hole:

PS C:\Users\Cetheus\AppData\Roaming\eDEX-UI> nslookup fritz.box pi.hole
Server:  pi.hole
Address:  192.168.178.10

Name:    fritz.box
Addresses:  fd00::3ea6:2fff:fef5:5aa2
          2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2
          192.168.1.1

ping Router via Hostname actually works (via IPv6):

PS C:\Users\Cetheus\AppData\Roaming\eDEX-UI> ping fritz.box
Ping wird ausgeführt für fritz.box [2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2] mit 32 Bytes Daten:
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms

Ping-Statistik für 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2:
    Pakete: Gesendet = 4, Empfangen = 4, Verloren = 0
    (0% Verlust),
Ca. Zeitangaben in Millisek.:
    Minimum = 1ms, Maximum = 1ms, Mittelwert = 1ms

but not via IPv4:

PS C:\Users\Cetheus\AppData\Roaming\eDEX-UI> ping fritz.box
Ping wird ausgeführt für fritz.box [2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2] mit 32 Bytes Daten:
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms
Antwort von 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2: Zeit=1ms

Ping-Statistik für 2a02:8108:8b40:bf64:3ea6:2fff:fef5:5aa2:
    Pakete: Gesendet = 4, Empfangen = 4, Verloren = 0
    (0% Verlust),
Ca. Zeitangaben in Millisek.:
    Minimum = 1ms, Maximum = 1ms, Mittelwert = 1ms

The IP-Setup is as following:

192.168.178.1 Router (Fritz.Box)
192.168.178.10 Pi-Hole (Raspberry Pi 3)
192.168.178.21 Windows PC (Windows 10)

IP-Setup (via DHCP through the Router):

Standardgateway . . . . . . . . . : fe80::3ea6:2fff:fef5:5aa2%5
                                       192.168.178.1
   DHCP-Server . . . . . . . . . . . : 192.168.178.1
   DHCPv6-IAID . . . . . . . . . . . : 74483138
   DHCPv6-Client-DUID. . . . . . . . : 00-01-00-01-27-DC-39-C6-70-85-C2-89-F8-DC
   DNS-Server  . . . . . . . . . . . : fe80::84b9:25b8:ffb3:6dbb%5
                                       192.168.178.10
                                       fe80::84b9:25b8:ffb3:6dbb%5

Expected Behaviour:

Resolving the Hostnames of my local Network, with or without the FQDN

Actual Behaviour:

I can't resolve any local Hostname only on my Windows 10 Systems.

Debug Token:

https://tricorder.pi-hole.net/LyPCALuj/

Thanks for any Help in advance.

Greetings Sascha

2

A bit off topic, but, Debian 10's EOL is ~2022-08, i.e next month. You should have updated to 11 (Bullseye).

1 Like
3

By default, Raspberry Pi OS generates stable IPv6 interface identifiers according to RFC7217 (instead of EUI64 ones that would contain and disclose a NICs MAC). They serve a similar purpose as RFC4941 IPv6 Privacy Extension interface ids, but unlike those, they are calculated by your OS only once and are generally designed to change only if the IPv6 prefix would change.

Now, it seems your OS update would have triggered to calculate those interface identifiers afresh:

*** [ DIAGNOSING ]: Network interfaces and addresses
   2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500        inet6 fe80::17ac:6b39:36c6:70f5/64 scope link

Likely, you are observing your network still sending DNS requests to the previous IPv6.

To address this, just update your Pi-hole's IPv6 in your router.

1 Like
4

I will do this update sometime in the next days. Thanks for the hint.

I just updated the IPv6.

image
image1304×197 20.6 KB

But it did not help:

nslookup fritz.box
DNS request timed out.
    timeout was 2 seconds.
Server:  UnKnown
Address:  fe80::84b9:25b8:ffb3:6dbb

DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Zeitüberschreitung bei Anforderung an UnKnown.

I also do not know the Address: fe80::84b9:25b8:ffb3:6dbb, my Windows is using when I perform a nslookup.
But if I ask my Fritz.Box or Pi.Hole both say, they can't resolve this IPv6.

When I 'ipconfig' my NIC, it says:

DNS-Server  . . . . . . . . . . . : fe80::84b9:25b8:ffb3:6dbb%5
                                       192.168.178.10
                                       fe80::17ac:6b39:36c6:70f5%5
                                       fe80::84b9:25b8:ffb3:6dbb%5

so it does get this Adress as a secondary DNS, if I'm right?

Did I make a mistake configuring my IPv6 Settings?

@Bucking_Horn Thankts for the Hint, I waited some time and now the resolving is working again.

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