Issue with core-dns in rke2.
Intermittent issues with DNS resolution, where the nslookup command sometimes succeeds and other times fails with a timeout.
DNS service IP (10.43.0.10) sometimes responds on port 53 and sometimes does not, suggests an intermittent issue with the CoreDNS service or the underlying network configuration in your RKE2 cluster.
root@rke-master1:~# k get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
rke-master1 Ready control-plane,etcd,master 4h49m v1.31.4+rke2r1 172.25.68.5 Ubuntu 22.04.4 LTS 5.15.0-119-generic containerd://1.7.23-k3s2
rke-master2 Ready control-plane,etcd,master 33m v1.31.4+rke2r1 172.25.68.6 Ubuntu 22.04.4 LTS 5.15.0-119-generic containerd://1.7.23-k3s2
rke-master3 Ready control-plane,etcd,master 21m v1.31.4+rke2r1 172.25.68.7 Ubuntu 22.04.4 LTS 5.15.0-119-generic containerd://1.7.23-k3s2
rke-worker1 Ready 3h10m v1.31.4+rke2r1 172.25.68.10 Ubuntu 22.04.4 LTS 5.15.0-119-generic containerd://1.7.23-k3s2
root@rke-master1:~# k get svc -n kube-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
rke2-coredns-rke2-coredns ClusterIP 10.43.0.10 53/UDP,53/TCP 4h49m
This issue with only if underlying infra is vcd but if i deploy same setup on openstack based cloud its working fine. So please suggest which parameter of vcd can blocking clusterip of codedns interment