Partially losing connection after Router reboot

English Networking
1

Hello.
I have a TS-264 on QTS 5.2.6.3195 connected to a GL.iNet Slate AX1800 Router via Ethernet.
Inside the NAS I host Home Assistant on a Virtual Machine plus several Docker containers, including AdGuard Home in Host mode using port 53.
I configured the Router to redirect all DNS queries to AdGuard Home.

When the Router does a scheduled reboot, I partially lose connectivity to the NAS.
What works: almost every Docker container and Home Assistant. I can access them locally.
What does not work: Accessing the NAS Web Interface or AdGuard Home, plus general internet connectivity because there is no valid DNS resolver for the router (AdGuard Home).

What I have to do in those cases is unplug and plug back the network cable that connects the NAS with the Router from both sides, only then everything works again.
I have tried replacing the network cable and using different LAN ports on both sides.
I also have tried Port Trunking as Failover, to see if the NAS can maintain connectivity but no luck.

Any other ideas that you can give me please?, thank you.

2

If replugging works, have you tried a switch?

Also you access the NAS via DNS? IP should work though…right ?

3

I can’t get a switch for the moment unfortunately.
I can’t access the NAS using the regular IP: 192.168.8.129:port
The thing is that before, maybe a couple of updates ago, the problem was not present but I cannot be sure if a QTS update was the cause either.

4

Weird…never heard of IP not working, but DNS local name does.

5 port 1GbE cost 10-15 bucks…not that much of a deterrent

5

I wonder what address the DNS is resolving to? Does it match the IP the OP is trying?

6

The Router is configured to direct DNS queries to 192.168.8.129:53, which is AdGuard Home.
I access the Qnap NAS Web Interface through 192.168.8.129:“port”.
It matches because it works as it is doing now, I can see the DNS queries being processed on AdGuard Home.

7

I don’t know if this helps, but I use pihole in docker. Don’t add the “:53”. just the ip.

8

Just re-read your OP to understand your config: it’s certainly creative!

  • Regarding the IP address returned by your DNS server, what does an nslookup show for your NAS hostname?

  • Are you using a static internal IP address for the router?

  • What is your QTS UI port number? Hiding it makes it difficult to assist you.

  • What address have you told your network devices to use for DNS resolution? The router or your NAS?

9

From a Windows machine:
nslookup 192.168.8.129
Server: NAS
Address: 192.168.8.129

From the Router:
Server: 127.0.0.1
Address: 127.0.0.1:53
129.8.168.192.in-addr.arpa name = NAS.lan

Everything in my network uses static IPs, otherwise it would be a nightmare.

The QTS port number is 460.

10

Why are you using a port number other than the standard 8080?

On the router the 127.0.0.1 address is the router’s local loopback address. So something appears to be wrong with the router.

And do you feel you need to have canonical domain names on your LAN? I just address everything by my IP addresses directly and you should see the network I have for my home.

11

No that is dropbear. OpenWRT would have resolv.conf setup to use it.