Hello,
lately I discovered a some strange behavior with the DNS of my openHAB installation.
After some time of running the system is not reachable using the hostname, but it works using the IP address. After rebooting the Raspberry Pi everything is fine for a while.
Router:
FRITZ!Box 7590
Firmware = 07.20
System:
Release = Raspbian GNU/Linux 10 (buster)
Kernel = Linux 5.4.51-v7l+
Platform = Raspberry Pi 4 Model B Rev 1.1
Memory = Free: 2.75GB (73%), Used: 1.03GB (27%), Total: 3.78GB
Root = Free: 23.48GB (85%), Used: 4.01GB (15%), Total: 28.99GB
Updates = 0 apt updates available.
openHAB:
openHAB 2.5.7-1 (Release Build)
Java:
OpenJDK Runtime Environment (Zulu 8.48.1.243-CA-linux_aarch32hf) (build 1.8.0_262-b17)
OpenJDK Client VM (Zulu 8.48.1.243-CA-linux_aarch32hf) (build 25.262-b17, mixed mode)
After rebooting the Raspberry Pi I get the following information looking up the IP address:
> nslookup 192.168.1.10
Server: 192.168.1.1
Address: 192.168.1.1#53
10.1.168.192.in-addr.arpa name = MYRASPPI.fritz.box.
10.1.168.192.in-addr.arpa name = MYRASPPI-fritz-box.fritz.box.
Actually I have no idea where the entry MYRASPPI-fritz-box comes from. I can not find it anywhere and I am quite sure, that I did not enter it anywhere like that.
Looking up the IP address later will result in:
> nslookup 192.168.1.10
Server: 192.168.1.1
Address: 192.168.1.1#53
10.1.168.192.in-addr.arpa name = MYRASPPI.fritz.box.
10.1.168.192.in-addr.arpa name = MYRASPPI-fritz-box.fritz.box.
10.1.168.192.in-addr.arpa name = JmDNS-/192-168-1-10.fritz.box.
Everything is still working in this state.
If I look up the IP address, when the system is not reachable by hostname anymore it will result:
> nslookup 192.168.1.10
Server: 192.168.1.1
Address: 192.168.1.1#53
10.1.168.192.in-addr.arpa name = MYRASPPI-fritz-box.fritz.box.
I understand, why I am not able to reach the system by hostname now, but why do the entries change during runtime?
During setup of the openHAB I set the Hostname to MYRASPPI.
In the FRITZ!Box router I bind the Raspberry Pi (by MAC address I think) to the name MYRASPPI and the IP address 192.168.1.10.
Rebooting the Raspberry Pi makes everything working again for a couple of hours.
I discovered the problem a few weeks ago.
It might be related to an update of the system, but I can’t say for sure, since I usually update every time , I am applying changes to the system.
It is not related to the latest Firmwareupdate of the FRITZ!Box, since I discovered the problem already with the 07.12 Firmware.
I do not discover anything similar withe any other of my network devices.
Does anyone discover something similar?
Does anyone has an idea how to find and solve the problem?