I understand that pods are isolated into another subnet (POD-CIDR, CNI...) Is that possible to reach a pod (using a tool)? I saw that you can use ClusterIP, LB, Externalname, but I cannot reach my pod's ipaddress.
Assuming you have a service defined for your pod (deployment) you can use kubectl to forward local ports to that service. For example:
$ kubectl port-forward redis-service 6379:6379 --namespace=default
This would allow you to access your pod/service through local port 6379
If you are interested in making your pod publicly available, your best resource would be to define an ingress. This will allow you to map a public DNS hostname and path to your internal kubernetes service
that means something is wrong with your networking. Kubernetes imposes the following fundamental requirements on any networking implementation (barring any intentional network segmentation policies):
https://kubernetes.io/docs/concepts/cluster-administration/networking/