So the MTU of Tailscale is actually 1280, but is the connection even going through the VPN or rather through my VPS, when Uptime-Kuma is trying to connect to my local domain?

Thanks, since I access my home network and server through the public IPv4 of a VPS via Tailscale this could actually be the issue. I’ll look into it, when I find the time.

Not sure how this helps, but here you go.

Yeah, I suspect it’s simply an issue on the side of DuckDNS. :/

Yeah, it works fine through my browser. Sometimes the websites load a little longer. I feel like it’s an issue with DuckDNS as it’s seemingly random when it works and when not.

IPv6 doesn’t work:

docker exec -it Uptime-Kuma curl -6 proxmox.datenprolet.duckdns.org
curl: (6) Could not resolve host: proxmox.datenprolet.duckdns.org

Besides that the issue has disappeares since last night. I automatically restart all containers at night and moved from uptime-kuma:1 to uptime-kuma:latest. That shouldn’t make a difference, but maybe it did?

And it’s not a typo in my config, but in my post. But good catch. ;)

It’s HTTPS, what else should it be, when I monitor a domain?

What do you mean by tracker? I’m monitoring local domains, that point to local services and their respective web interfaces like Proxmox or Nextcloud. The local domains have a wildcard SSL certificate via DuckDNS.

Well, I’m monitoring the GUI of Proxmox on which I run a Debian VM which itself runs Uptime-Kuma and Nextcloud in Docker, so yes that’s on the same hardware.

Yep

Yes, Uptime-Kuma is running on the same domain as the other services, except the Nginx-Proxy-Manager, which runs on a VPS which I access via WireGuard. And yes, I’m using Docker. I tried curl’ing one of the domains from the Uptime-Kuma container and got the folllowing error: curl: (35) OpenSSL SSL_connect: SSL_ERROR_SYSCALL in connection to service.datenprolet.duckdns.org:443. So thanks, now I have an idea about what I should investigate.

But it’s proprietary, unfortunately.

I don’t want to configure a whole Dashboard for at least CPU, RAM, Storage and Network for up to 5 hosts.

I used the following dashboard now, but it’s not really satisfying and also doesn’t really fit more than 4 nodes. https://grafana.com/grafana/dashboards/11756-hpc-node-exporter-server-metrics-v2/

Oh boy have I bad news for you. You ever heard of copyright?

You’re technically right, but nobody anticipated and therefore agreed on their posts being used for training LLMs.

Full on conspiracy?

there are hidden interests and hands that pull the strings of the dynamics that are harmful

Yes I’m running it on Docker and therefore have the docker0 interface.

Are you sure Tailscale in Docker is creating a wg0 interface? Because I got a working connection between my smartphone and my home server and the home server is not showing any interface related to Tailscale?

default via 192.168.178.1 dev ens18 
172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1 
192.168.178.0/24 dev ens18 proto kernel scope link src 192.168.178.178 

Thanks, that’s what I’m trying to do. :)

And my VPS doesn’t have any IPs in the same range as my home server.

How do I make sure of this? What am I supposed to see using the command?