Kubernetes Network Issues

Hello,

Im a Nix newbie and recently started diving deeper with NixOps and I’m currently trying to set up a small two node k8s cluster.

Unfortunately I’m having some network issues between the second and master node.
I can ping pods which are on the same node, but can’t ping pods which are on the other node. As such, I’m also unable to use CoreDNS on the second node.

After a bit of debugging with tcpdump I found out that the traffic is received on the other node, but the pod didn’t receive it (coredns with log enabled shows nothing no requests from the other node).

I’ve already disabled the firewall networking.firewall.enable = false;, which unfortunately didn’t improve the situation.

Both nodes are on NixOS 20.03 and I used the documentation from the NixOs wiki
https://nixos.wiki/wiki/Kubernetes