How to access a created cluster without Rancher?

Rancher 2.x
1

How to access a K8S API on a RKE2 cluster created by Rancher v2.6 on vSphere without Rancher?

I want to install a load balancer in front of K8S API management nodes for a cluster created by Rancher, then access it through this load balancer.
Simply changing DNS name in kubeconfig file downloaded from Rancher GUI does not work.
I got an error:
Unable to connect to the server: X.509 certificate signed by unknown authority

2

You are looking for Authorized Cluster Endpoint as it allows you to add a secondary kube-api endpoint for your kubeconfigs that are created in Rancher.

You basically need to create a TCP load balancer that sits in front of your master/control-plane nodes and forwards port 6443. Then for the RKE2 part, please see High Availability - RKE2 - Rancher's Next Generation Kubernetes Distribution.