Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Nicholas Geovanis 
On Wed, Mar 31, 2021, 4:26 PM Moritz Kempe 
wrote:

> Up until now i used my AVM Fritz!Box (my router) with the (supported)
> firmware version FRITZ!OS-Version 07.21.
>
> Just now, i upgraded the firmware to FRITZ!OS-Version 07.25 and the DNS
> is now working on my Raspberry Pi 400.
>
>
> I cannot yet say, if my problem is solved but it seems like it. I will
> reply to this mail if the problem will reoccur
>

Wow, you're fast :-)
I feared you would find exactly those long DHCP discover sequences that you
noticed. I was just going back to see if the server that granted you was at
the address you were expecting.
Gruß Gott

Here is an changelog
> https://en.avm.de/fritz-lab/fresh-from-development/updates-improvements/
>
> > *Improved *- Update process more robust for potential DNS problems
> Or here in the German changelog
>
> https://avm.de/service/downloads/update-news/download/show/eyJkaXNwbGF5IjoiRlJJVFohQm94IDc1OTAiLCJ1cmwiOiJodHRwOlwvXC9kb3dubG9hZC5hdm0uZGVcL2ZyaXR6Ym94XC9mcml0emJveC03NTkwXC9kZXV0c2NobGFuZFwvZnJpdHoub3NcL2luZm9fZGUudHh0IiwiaGFzaCI6IjNiYmQ1ZTI5YTg4N2NjM2U3ZjRhZTRhOTY4YjE3OTNmYTA2MWU1NzA1Y2NkYjZlYjA2ODM2NWYwNjEzYWMzZjcifQ%3D%3D/
>
>
> *Behoben* IPv6: Im IPv6 Router Advertisement (RA) mit Option 25
> (Recursive DNS Server) wurden zum Teil Bits des Feldes "Reserved" gesetzt
>
> [EN] Fixed: IPv6 Router Advertisement (RA) with Option 25 (Recursive DNS
> Server) got manipulated bits at the field "Reserved"
>
>
> *Behoben* DNS-Anfragen des Typs "PTR" wurden teilweise nicht korrekt
> aufgelöst
>
> [EN] Fixed: DNS Querries with Type "PTR" wouldn't get resolved right.
>
>
> Could on of this changes be the cause of my problems, or the problems
> other people are also getting?
>
>

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Moritz Kempe 
Up until now i used my AVM Fritz!Box (my router) with the (supported) 
firmware version FRITZ!OS-Version 07.21.


Just now, i upgraded the firmware to FRITZ!OS-Version 07.25 and the DNS 
is now working on my Raspberry Pi 400.



I cannot yet say, if my problem is solved but it seems like it. I will 
reply to this mail if the problem will reoccur.



Here is an changelog 
https://en.avm.de/fritz-lab/fresh-from-development/updates-improvements/



*Improved *- Update process more robust for potential DNS problems
Or here in the German changelog 
https://avm.de/service/downloads/update-news/download/show/eyJkaXNwbGF5IjoiRlJJVFohQm94IDc1OTAiLCJ1cmwiOiJodHRwOlwvXC9kb3dubG9hZC5hdm0uZGVcL2ZyaXR6Ym94XC9mcml0emJveC03NTkwXC9kZXV0c2NobGFuZFwvZnJpdHoub3NcL2luZm9fZGUudHh0IiwiaGFzaCI6IjNiYmQ1ZTI5YTg4N2NjM2U3ZjRhZTRhOTY4YjE3OTNmYTA2MWU1NzA1Y2NkYjZlYjA2ODM2NWYwNjEzYWMzZjcifQ%3D%3D/



*Behoben* IPv6: Im IPv6 Router Advertisement (RA) mit Option 25 
(Recursive DNS Server) wurden zum Teil Bits des Feldes "Reserved" gesetzt


[EN] Fixed: IPv6 Router Advertisement (RA) with Option 25 (Recursive DNS 
Server) got manipulated bits at the field "Reserved"



*Behoben* DNS-Anfragen des Typs "PTR" wurden teilweise nicht korrekt 
aufgelöst


[EN] Fixed: DNS Querries with Type "PTR" wouldn't get resolved right.


Could on of this changes be the cause of my problems, or the problems 
other people are also getting?

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Moritz Kempe 

On 3/31/21 3:22 PM, Nicholas Geovanis wrote:
On Wed, Mar 31, 2021, 8:08 AM Moritz Kempe > wrote:


On 3/31/21 1:55 PM, Lee wrote:
> On 3/31/21, Moritz Kempe mailto:deblist%2bdeb...@moke12g.de>> wrote:
>> On 3/31/21 1:25 PM, Greg Wooledge wrote:
>>> On Wed, Mar 31, 2021 at 12:14:59AM +0200, Moritz Kempe wrote:
 -- Firefox Hmm. We’re having trouble finding that site. We can’t
 connect to the server at github.com .
 -- Chromium This site can’t be reachedCheck if there is a typo in
 github.com . DNS_PROBE_FINISHED_NXDOMAIN
 moke@rpi4-20201112:~$ host github.com 
Host github.com  not found:
 2(SERVFAIL)
>>> grep ^hosts: /etc/nsswitch.conf
>> --
>> hosts:          files mdns4_minimal [NOTFOUND=return] dns
mymachines
> I don't trust multicast dns, so in addition to turning it off
I've also got
> $ grep host /etc/nsswitch.conf
> # hosts:          files mdns4_minimal [NOTFOUND=return] dns
> hosts:          files dns
>
> Maybe worth a shot?

Changed my /etc/nsswitch.conf to

--

..

#hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines
hosts:  files dns
..

--

and rebooted the system. The behavior hasn't changed.

github.com  is still blocked. And dig is still
able to find the ip address.

Or do i have done something wrong?


I have found out, that i can restore some domains when running
"/sbin/dhclient" as root but not all. Github is still not accessible.


That's why I suggested checking for DHCP messages in the logs. But 
also logs upstream from your pi's. Each time you get a DHCP grant, 
potentially you've switched DNS servers.


Do you mean the logs at /var/log/syslog?

And for what i look out for?

Here are some entries, maybe you see something important for this issue.

--

Mar 31 14:39:04 rpi4-20201112 dhclient[5538]: DHCPDISCOVER on docker0 to 
255.255.255.255 port 67 interval 7
Mar 31 14:39:11 rpi4-20201112 dhclient[5538]: DHCPDISCOVER on docker0 to 
255.255.255.255 port 67 interval 20
Mar 31 14:39:31 rpi4-20201112 dhclient[5538]: DHCPDISCOVER on docker0 to 
255.255.255.255 port 67 interval 12
Mar 31 14:39:43 rpi4-20201112 dhclient[5538]: DHCPDISCOVER on docker0 to 
255.255.255.255 port 67 interval 19
Mar 31 14:40:02 rpi4-20201112 dhclient[5538]: DHCPDISCOVER on docker0 to 
255.255.255.255 port 67 interval 3

Mar 31 14:40:05 rpi4-20201112 dhclient[5538]: No DHCPOFFERS received.
Mar 31 14:40:05 rpi4-20201112 dhclient[5538]: No working leases in 
persistent database - sleeping.


-- This was logged for many times.

--

Mar 31 15:05:49 rpi4-20201112 dhclient[478]: Internet Systems Consortium 
DHCP Client 4.4.1
Mar 31 15:05:49 rpi4-20201112 dhclient[478]: Copyright 2004-2018 
Internet Systems Consortium.
Mar 31 15:05:49 rpi4-20201112 ifup[478]: For info, please visit 
https://www.isc.org/software/dhcp/

Mar 31 15:05:49 rpi4-20201112 dhclient[478]: All rights reserved.
Mar 31 15:05:49 rpi4-20201112 dhclient[478]: For info, please visit 
https://www.isc.org/software/dhcp/

Mar 31 15:05:49 rpi4-20201112 dhclient[478]:
Mar 31 15:05:49 rpi4-20201112 dhclient[478]: Listening on 
LPF/eth0/##:##:##:##:##:##    # censored by me
Mar 31 15:05:49 rpi4-20201112 dhclient[478]: Sending on 
LPF/eth0/##:##:##:##:##:## # censored by me

Mar 31 15:05:49 rpi4-20201112 dhclient[478]: Sending on Socket/fallback
Mar 31 15:05:49 rpi4-20201112 dhclient[478]: DHCPDISCOVER on eth0 to 
255.255.255.255 port 67 interval 8
Mar 31 15:05:50 rpi4-20201112 NetworkManager[417]:  
[1617195950.2281] dhcp-init: Using DHCP client 'internal'
Mar 31 15:05:57 rpi4-20201112 dhclient[478]: DHCPDISCOVER on eth0 to 
255.255.255.255 port 67 interval 14
Mar 31 15:05:58 rpi4-20201112 dhclient[478]: DHCPOFFER of 10.0.0.70 from 
10.0.0.1
Mar 31 15:05:58 rpi4-20201112 dhclient[478]: DHCPREQUEST for 10.0.0.70 
on eth0 to 255.255.255.255 port 67
Mar 31 15:05:58 rpi4-20201112 dhclient[478]: DHCPACK of 10.0.0.70 from 
10.0.0.1
Mar 31 15:06:38 rpi4-20201112 dhclient[478]: bound to 10.0.0.70 -- 
renewal in 3831703 seconds.


--

I used the command "cat /var/log/syslog | grep dhc"


And you said


But also logs upstream from your pi's.
do you mean the DHCP log from my router? Because i searched for one, but 
i haven't found one yet.


Or do you mean that i should use Wireshark to analyze my DHCP requests?


I haven't looked into networking on that level.

I would be nice, if you would give me an explanation or link a website 
which could do that.




Note: I haven't changed any networking configuration on this
device. I
haven't even enabled wifi.

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Nicholas Geovanis 
On Wed, Mar 31, 2021, 8:08 AM Moritz Kempe 
wrote:

> On 3/31/21 1:55 PM, Lee wrote:
> > On 3/31/21, Moritz Kempe  wrote:
> >> On 3/31/21 1:25 PM, Greg Wooledge wrote:
> >>> On Wed, Mar 31, 2021 at 12:14:59AM +0200, Moritz Kempe wrote:
>  -- Firefox Hmm. We’re having trouble finding that site. We can’t
>  connect to the server at github.com.
>  -- Chromium This site can’t be reachedCheck if there is a typo in
>  github.com. DNS_PROBE_FINISHED_NXDOMAIN
>  moke@rpi4-20201112:~$ host github.com Host github.com not found:
>  2(SERVFAIL)
> >>> grep ^hosts: /etc/nsswitch.conf
> >> --
> >> hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines
> > I don't trust multicast dns, so in addition to turning it off I've also
> got
> > $ grep host /etc/nsswitch.conf
> > # hosts:  files mdns4_minimal [NOTFOUND=return] dns
> > hosts:  files dns
> >
> > Maybe worth a shot?
>
> Changed my /etc/nsswitch.conf to
>
> --
>
> ..
>
> #hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines
> hosts:  files dns
> ..
>
> --
>
> and rebooted the system. The behavior hasn't changed.
>
> github.com is still blocked. And dig is still able to find the ip address.
>
> Or do i have done something wrong?
>
>
> I have found out, that i can restore some domains when running
> "/sbin/dhclient" as root but not all. Github is still not accessible.
>

That's why I suggested checking for DHCP messages in the logs. But also
logs upstream from your pi's. Each time you get a DHCP grant, potentially
you've switched DNS servers.

Note: I haven't changed any networking configuration on this device. I
> haven't even enabled wifi.
>
>

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Moritz Kempe 

On 3/31/21 2:44 PM, Greg Wooledge wrote:

On Wed, Mar 31, 2021 at 01:42:36PM +0200, Moritz Kempe wrote:

grep ^hosts: /etc/nsswitch.conf

--
hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines

I don't know what "mymachines" is.  I don't see it in the man page.

What happens if you get rid of the "mymachines" field?


I have restarted my device with "mymachines" commented out.

It seems like, it behaviors the same.


-rw-r--r-- 1 root root 54 Mar 31 13:28 /etc/resolv.conf
domain fritz.box
search fritz.box
nameserver 10.0.0.1

You're using a local caching resolver, or at least something that
forwards requests.  That's fine, if it works.  You might try probing
the DNS resolver at 10.0.0.1 to see whether it actually does work.


Do you mean like so?

--

moke@rpi4-20201112:~$ dig @10.0.0.1 debian.org

; <<>> DiG 9.16.13-Debian <<>> @10.0.0.1 debian.org
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 13415
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;debian.org.            IN    A

;; ANSWER SECTION:
debian.org.        300    IN    A    149.20.4.15
debian.org.        300    IN    A    130.89.148.77
debian.org.        300    IN    A    128.31.0.62

;; Query time: 351 msec
;; SERVER: 10.0.0.1#53(10.0.0.1)
;; WHEN: Wed Mar 31 15:11:15 CEST 2021
;; MSG SIZE  rcvd: 87
--


(There's a really good chance that 10.0.0.1 is your router, and that
your router implements a forwarding nameserver, which just passes
your requests to your ISP.  These router-based forwarding resolvers
can be a bit flaky sometimes.)

Yes, 10.0.0.1 is my router.

; <<>> DiG 9.16.13-Debian <<>> @8.8.8.8 www.debian.org
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20269
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;www.debian.org.            IN    A

;; ANSWER SECTION:
www.debian.org.        229    IN    A 130.89.148.77
www.debian.org.        229    IN    A 149.20.4.15
www.debian.org.        229    IN    A 128.31.0.62

;; Query time: 35 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Wed Mar 31 13:38:10 CEST 2021
;; MSG SIZE  rcvd: 91

That's good.  At least you're not blocking UDP packets or something like
that.  If the weird entry in nsswitch.conf doesn't turn out to be the
problem, and 10.0.0.1 turns out to be non-functional in some way, you
could use Google's resolvers as a fallback.


Yes, i could add a fallback resolver to every device but the advantage 
of the router is, that you can set a dns server for a whole network 
which is a feature i do not want to miss. Also is there still the 
question, why Debian on the Raspberry Pi 400 can't use a dns server, 
which can be used by all other devices.

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Moritz Kempe 

On 3/31/21 1:55 PM, Lee wrote:

On 3/31/21, Moritz Kempe  wrote:

On 3/31/21 1:25 PM, Greg Wooledge wrote:

On Wed, Mar 31, 2021 at 12:14:59AM +0200, Moritz Kempe wrote:

-- Firefox Hmm. We’re having trouble finding that site. We can’t
connect to the server at github.com.
-- Chromium This site can’t be reachedCheck if there is a typo in
github.com. DNS_PROBE_FINISHED_NXDOMAIN
moke@rpi4-20201112:~$ host github.com Host github.com not found:
2(SERVFAIL)

grep ^hosts: /etc/nsswitch.conf

--
hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines

I don't trust multicast dns, so in addition to turning it off I've also got
$ grep host /etc/nsswitch.conf
# hosts:  files mdns4_minimal [NOTFOUND=return] dns
hosts:  files dns

Maybe worth a shot?


Changed my /etc/nsswitch.conf to

--

..

#hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines
hosts:  files dns
..

--

and rebooted the system. The behavior hasn't changed.

github.com is still blocked. And dig is still able to find the ip address.

Or do i have done something wrong?


I have found out, that i can restore some domains when running 
"/sbin/dhclient" as root but not all. Github is still not accessible.



Note: I haven't changed any networking configuration on this device. I 
haven't even enabled wifi.

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Greg Wooledge 
On Wed, Mar 31, 2021 at 01:42:36PM +0200, Moritz Kempe wrote:
> > grep ^hosts: /etc/nsswitch.conf
> --
> hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines

I don't know what "mymachines" is.  I don't see it in the man page.

What happens if you get rid of the "mymachines" field?

> -rw-r--r-- 1 root root 54 Mar 31 13:28 /etc/resolv.conf

> domain fritz.box
> search fritz.box
> nameserver 10.0.0.1

You're using a local caching resolver, or at least something that
forwards requests.  That's fine, if it works.  You might try probing
the DNS resolver at 10.0.0.1 to see whether it actually does work.

(There's a really good chance that 10.0.0.1 is your router, and that
your router implements a forwarding nameserver, which just passes
your requests to your ISP.  These router-based forwarding resolvers
can be a bit flaky sometimes.)

> ; <<>> DiG 9.16.13-Debian <<>> @8.8.8.8 www.debian.org
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20269
> ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
> 
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 512
> ;; QUESTION SECTION:
> ;www.debian.org.            IN    A
> 
> ;; ANSWER SECTION:
> www.debian.org.        229    IN    A 130.89.148.77
> www.debian.org.        229    IN    A 149.20.4.15
> www.debian.org.        229    IN    A 128.31.0.62
> 
> ;; Query time: 35 msec
> ;; SERVER: 8.8.8.8#53(8.8.8.8)
> ;; WHEN: Wed Mar 31 13:38:10 CEST 2021
> ;; MSG SIZE  rcvd: 91

That's good.  At least you're not blocking UDP packets or something like
that.  If the weird entry in nsswitch.conf doesn't turn out to be the
problem, and 10.0.0.1 turns out to be non-functional in some way, you
could use Google's resolvers as a fallback.

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Lee 
On 3/31/21, Moritz Kempe  wrote:
> On 3/31/21 1:25 PM, Greg Wooledge wrote:
>> On Wed, Mar 31, 2021 at 12:14:59AM +0200, Moritz Kempe wrote:
>>> -- Firefox Hmm. We’re having trouble finding that site. We can’t
>>> connect to the server at github.com.
>>> -- Chromium This site can’t be reachedCheck if there is a typo in
>>> github.com. DNS_PROBE_FINISHED_NXDOMAIN
>>> moke@rpi4-20201112:~$ host github.com Host github.com not found:
>>> 2(SERVFAIL)
>> grep ^hosts: /etc/nsswitch.conf
> --
> hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines

I don't trust multicast dns, so in addition to turning it off I've also got
$ grep host /etc/nsswitch.conf
# hosts:  files mdns4_minimal [NOTFOUND=return] dns
hosts:  files dns

Maybe worth a shot?

Regards,
Lee

>
> --
>
>
>> ls -ld /etc/resolv.conf
> --
> -rw-r--r-- 1 root root 54 Mar 31 13:28 /etc/resolv.conf
> --
>
>> cat /etc/resolv.conf
> --
> domain fritz.box
> search fritz.box
> nameserver 10.0.0.1
> --
>
>> dig @8.8.8.8 www.debian.org
> --
> ; <<>> DiG 9.16.13-Debian <<>> @8.8.8.8 www.debian.org
> ; (1 server found)
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20269
> ;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 512
> ;; QUESTION SECTION:
> ;www.debian.org.INA
>
> ;; ANSWER SECTION:
> www.debian.org.229INA 130.89.148.77
> www.debian.org.229INA 149.20.4.15
> www.debian.org.229INA 128.31.0.62
>
> ;; Query time: 35 msec
> ;; SERVER: 8.8.8.8#53(8.8.8.8)
> ;; WHEN: Wed Mar 31 13:38:10 CEST 2021
> ;; MSG SIZE  rcvd: 91
>
> --
>
>
> I hope i interpreted your mail in the right way.
>
>

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Moritz Kempe 

On 3/31/21 1:25 PM, Greg Wooledge wrote:

On Wed, Mar 31, 2021 at 12:14:59AM +0200, Moritz Kempe wrote:
-- Firefox Hmm. We’re having trouble finding that site. We can’t 
connect to the server at github.com. 
-- Chromium This site can’t be reachedCheck if there is a typo in 
github.com. DNS_PROBE_FINISHED_NXDOMAIN 
moke@rpi4-20201112:~$ host github.com Host github.com not found: 
2(SERVFAIL) 

grep ^hosts: /etc/nsswitch.conf

--
hosts:  files mdns4_minimal [NOTFOUND=return] dns mymachines

--



ls -ld /etc/resolv.conf

--
-rw-r--r-- 1 root root 54 Mar 31 13:28 /etc/resolv.conf
--


cat /etc/resolv.conf

--
domain fritz.box
search fritz.box
nameserver 10.0.0.1
--


dig @8.8.8.8 www.debian.org

--
; <<>> DiG 9.16.13-Debian <<>> @8.8.8.8 www.debian.org
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 20269
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;www.debian.org.            IN    A

;; ANSWER SECTION:
www.debian.org.        229    IN    A 130.89.148.77
www.debian.org.        229    IN    A 149.20.4.15
www.debian.org.        229    IN    A 128.31.0.62

;; Query time: 35 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Wed Mar 31 13:38:10 CEST 2021
;; MSG SIZE  rcvd: 91

--


I hope i interpreted your mail in the right way.

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Greg Wooledge 
On Wed, Mar 31, 2021 at 12:14:59AM +0200, Moritz Kempe wrote:
> -- Firefox
> Hmm. We’re having trouble finding that site.
> 
> We can’t connect to the server at github.com.

> -- Chromium
> This site can’t be reachedCheck if there is a typo in github.com.
> DNS_PROBE_FINISHED_NXDOMAIN

> moke@rpi4-20201112:~$ host github.com
> Host github.com not found: 2(SERVFAIL)

grep ^hosts: /etc/nsswitch.conf
ls -ld /etc/resolv.conf
cat /etc/resolv.conf
dig @8.8.8.8 www.debian.org

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Moritz Kempe 

Am 31.03.21 um 09:23 schrieb Klaus Singvogel:

Moritz Kempe wrote:
[...]

I noticed the problem, while i was browsing the internet and got confused
because after a while some domains could not longer be found/connected to by
the browser. (On both, Firefox and Chromium)

I had similar issues, when I changed DNS configuration at my DSL router.

I enabled on my DSL router: TLS for DNS, and, parallel, switched to
public, non-censored DNS servers, as suggested by a large German computer
magazine.
I've done this too. I also activated dns over tls with a privacy dns 
server in my router but i haven't mentioned it because it, doesn't 
seemed like there was any connection between these changes. On all other 
devices this works just fine. And even when i change my dns server to 
the default one, the raspberry pi still has these problems. (I tested 
this before i wrote the first mail)

Those DNS servers were independent and respect more privacy, compared to
my ISP. But after a while I noticed, that those public DNS servers drop
requests and I saw your error messages at my side too, especially if there
were a lot of name resolutions in a short time period.


On my raspberry pi 400, this could be the case, but on my Debian Stretch 
PC it works just fine.


I do experience these issues only on my raspberry pi 400, with both of 
my operating systems.



Those errors vanished after a while (several minutes) and everything
worked as expected. But then, when resolving again a lot of domain names,
the issues were back. Especially when I download from S3 Amazon, because
the IP address for s3.[...].amazon.com changes every 10 seconds or so.


On my raspberry pi 400 they occurre and rarely fix themselves but the 
majority of these stays up for all eternity (or up to an shutdown).
It don't feels, like you described, it is more like an blocklist which 
is getting longer and longer (and forces me to use google when my 
favorite search engines are blocked).



Don't know, if both are related.

But my suggestion is to look at your DSL router: if you changed the
defaults for DNS, and, if so, switch back to original, default setting for
testing purpose.
I switched my routers dns server back to the ISPs and also rebootet my 
device.
But i wasn't able to get on github.com but at the same time i was able 
to get on the by the (German) CUII (Clearingstelle Urheberrecht im 
Internet) censored site s.to [0] which shouldn't be accessible because 
of the censoring from my ISP.

This worked with both my browsers, firefox and chromium.


Regards,
Klaus.


[0] i do not encourage anyone to watch (illegal) content on s.to, i only 
chose this domain to test if i am able to visit censored websites.

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Moritz Kempe 

Am 31.03.21 um 09:23 schrieb Klaus Singvogel:

Moritz Kempe wrote:
[...]

I noticed the problem, while i was browsing the internet and got confused
because after a while some domains could not longer be found/connected to by
the browser. (On both, Firefox and Chromium)

I had similar issues, when I changed DNS configuration at my DSL router.

I enabled on my DSL router: TLS for DNS, and, parallel, switched to
public, non-censored DNS servers, as suggested by a large German computer
magazine.
I've done this too. I also activated dns over tls with a privacy dns 
server in my router but i haven't mentioned it because it, doesn't 
seemed like there was any connection between these changes. On all other 
devices this works just fine. And even when i change my dns server to 
the default one, the raspberry pi still has these problems. (I tested 
this before i wrote the first mail)

Those DNS servers were independent and respect more privacy, compared to
my ISP. But after a while I noticed, that those public DNS servers drop
requests and I saw your error messages at my side too, especially if there
were a lot of name resolutions in a short time period.


On my raspberry pi 400, this could be the case, but on my Debian Stretch 
PC it works just fine.


I do experience these issues only on my raspberry pi 400, with both of 
my operating systems.



Those errors vanished after a while (several minutes) and everything
worked as expected. But then, when resolving again a lot of domain names,
the issues were back. Especially when I download from S3 Amazon, because
the IP address for s3.[...].amazon.com changes every 10 seconds or so.


On my raspberry pi 400 they occurre and rarely fix themselves but the 
majority of these stays up for all eternity (or up to an shutdown).
It don't feels, like you described, it is more like an blocklist which 
is getting longer and longer (and forces me to use google when my 
favorite search engines are blocked).



Don't know, if both are related.

But my suggestion is to look at your DSL router: if you changed the
defaults for DNS, and, if so, switch back to original, default setting for
testing purpose.
I switched my routers dns server back to the ISPs and also rebootet my 
device.
But i wasn't able to get on github.com but at the same time i was able 
to get on the by the (German) CUII (Clearingstelle Urheberrecht im 
Internet) censored site s.to [0] which shouldn't be accessible because 
of the censoring from my ISP.

This worked with both my browsers, firefox and chromium.


Regards,
Klaus.


[0] i do not encourage anyone to watch (illegal) content on s.to, i only 
chose this domain to test if i am able to visit censored websites.

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-31 Thread Klaus Singvogel 
Moritz Kempe wrote:
[...]
> I noticed the problem, while i was browsing the internet and got confused
> because after a while some domains could not longer be found/connected to by
> the browser. (On both, Firefox and Chromium)

I had similar issues, when I changed DNS configuration at my DSL router.

I enabled on my DSL router: TLS for DNS, and, parallel, switched to
public, non-censored DNS servers, as suggested by a large German computer
magazine.

Those DNS servers were independent and respect more privacy, compared to
my ISP. But after a while I noticed, that those public DNS servers drop
requests and I saw your error messages at my side too, especially if there
were a lot of name resolutions in a short time period.

Those errors vanished after a while (several minutes) and everything
worked as expected. But then, when resolving again a lot of domain names,
the issues were back. Especially when I download from S3 Amazon, because
the IP address for s3.[...].amazon.com changes every 10 seconds or so.

Don't know, if both are related.

But my suggestion is to look at your DSL router: if you changed the
defaults for DNS, and, if so, switch back to original, default setting for
testing purpose.

Regards,
Klaus.
-- 
Klaus Singvogel
GnuPG-Key-ID: 1024R/5068792D  1994-06-27

Re: DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-30 Thread Nicholas Geovanis 
On Tue, Mar 30, 2021, 5:33 PM Moritz Kempe  wrote:

> Hello,
>
> since i upgraded my Raspberry Pi 400 (with regular Debian 10, not
> Raspberry PI OS) to the latest buster version, i am experiencing
> problems with dns, which i cannot replicate with any of my other devices
> (Debian Stretch amd64 workstation, Debian Buster amd64 server, Raspberry
> Pi 3b armhf raspberrypi OS). But i can replicate this behavior with
> another another micro sd flashcard with Twister OS on the (same)
> Raspberry Pi 400. Twister OS is an Debian / Raspberry Pi OS based OS
> which helps you to game on the Raspberry Pi 400.
>
> I noticed the problem, while i was browsing the internet and got
> confused because after a while some domains could not longer be
> found/connected to by the browser. (On both, Firefox and Chromium)
>
> -- Firefox
> Hmm. We’re having trouble finding that site.
>
> We can’t connect to the server at github.com.
>
> If that address is correct, here are three other things you can try:
>
>  Try again later.
>  Check your network connection.
>  If you are connected but behind a firewall, check that Firefox has
> permission to access the Web.
> --
>
> -- Chromium
> This site can’t be reachedCheck if there is a typo in github.com.
> DNS_PROBE_FINISHED_NXDOMAIN
> --
>
> And as time passes, more and more website will disappear.
> Which means, that after a hour only barely visited domains are left.
>
> And even stranger is the output of different dns tools:
>

Never saw that before said the man on fire :-) So just guesses:

Some weird DNS TTL issue? Or TTL incompatibility?
Strange DNS local caching issue? Maybe check resolv.conf and name service
config for new options or something.
Do you see any unexpected DHCP messages in the logs, maybe further upstream
from the pi's?

-- host github.com
> moke@rpi4-20201112:~$ host github.com
> Host github.com not found: 2(SERVFAIL)
> --
>
> -- dig github.com
> ; <<>> DiG 9.16.13-Debian <<>> github.com
> ;; global options: +cmd
> ;; Got answer:
> ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 30900
> ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
>
> ;; OPT PSEUDOSECTION:
> ; EDNS: version: 0, flags:; udp: 1232
> ;; QUESTION SECTION:
> ;github.com.IN  A
>
> ;; ANSWER SECTION:
> github.com. 27  IN  A   140.82.121.3
>
> ;; Query time: 343 msec
> ;; SERVER: 10.0.0.1#53(10.0.0.1)
> ;; WHEN: Tue Mar 30 23:31:01 CEST 2021
> ;; MSG SIZE  rcvd: 55
> --
>
> Dig seems to be able to get the ip from github.com but (the program)
> host, firefox and chromium can't.
>
> Some system information
>
> --
> moke@rpi4-20201112
> --
> OS: Debian GNU/Linux bullseye/sid aarch64
> Host: Raspberry Pi 400 Rev 1.0
> Kernel: 5.10.0-5-arm64
> Resolution: 1440x900, 1280x1024
> WM: awesome
> CPU: (4) @ 1.800GHz
> Memory: 606MiB / 3791MiB
> --
>
> My Raspberry Pi 400 is connected over Ethernet to my home router.
>
> Is there someone else, who experiences / has experienced this problem?
>
> PS: After i reboot the system all domains get unlocked (until they get
> locked again).
>
> Kind Regards
> Moritz Kempe
>
>

DNS problems on Raspberry Pi 400 (Debian 10.9)

2021-03-30 Thread Moritz Kempe 

Hello,

since i upgraded my Raspberry Pi 400 (with regular Debian 10, not 
Raspberry PI OS) to the latest buster version, i am experiencing 
problems with dns, which i cannot replicate with any of my other devices 
(Debian Stretch amd64 workstation, Debian Buster amd64 server, Raspberry 
Pi 3b armhf raspberrypi OS). But i can replicate this behavior with 
another another micro sd flashcard with Twister OS on the (same) 
Raspberry Pi 400. Twister OS is an Debian / Raspberry Pi OS based OS 
which helps you to game on the Raspberry Pi 400.


I noticed the problem, while i was browsing the internet and got 
confused because after a while some domains could not longer be 
found/connected to by the browser. (On both, Firefox and Chromium)


-- Firefox
Hmm. We’re having trouble finding that site.

We can’t connect to the server at github.com.

If that address is correct, here are three other things you can try:

Try again later.
Check your network connection.
If you are connected but behind a firewall, check that Firefox has 
permission to access the Web.

--

-- Chromium
This site can’t be reachedCheck if there is a typo in github.com.
DNS_PROBE_FINISHED_NXDOMAIN
--

And as time passes, more and more website will disappear.
Which means, that after a hour only barely visited domains are left.

And even stranger is the output of different dns tools:

-- host github.com
moke@rpi4-20201112:~$ host github.com
Host github.com not found: 2(SERVFAIL)
--

-- dig github.com
; <<>> DiG 9.16.13-Debian <<>> github.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 30900
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
;; QUESTION SECTION:
;github.com.IN  A

;; ANSWER SECTION:
github.com. 27  IN  A   140.82.121.3

;; Query time: 343 msec
;; SERVER: 10.0.0.1#53(10.0.0.1)
;; WHEN: Tue Mar 30 23:31:01 CEST 2021
;; MSG SIZE  rcvd: 55
--

Dig seems to be able to get the ip from github.com but (the program) 
host, firefox and chromium can't.


Some system information

--
moke@rpi4-20201112
--
OS: Debian GNU/Linux bullseye/sid aarch64
Host: Raspberry Pi 400 Rev 1.0
Kernel: 5.10.0-5-arm64
Resolution: 1440x900, 1280x1024
WM: awesome
CPU: (4) @ 1.800GHz
Memory: 606MiB / 3791MiB
--

My Raspberry Pi 400 is connected over Ethernet to my home router.

Is there someone else, who experiences / has experienced this problem?

PS: After i reboot the system all domains get unlocked (until they get 
locked again).


Kind Regards
Moritz Kempe