Hi Jinwook
This is the ip address and port on which your Kube cluster listens to incoming traffic. You can telnet there and see something like
telnet 192.168.99.100 2380
Trying 192.168.99.100…
Connected to minikube.local.
Escape character is ‘^]’.
In my case it is just Minikube installation, with same ingress/nginx installed. Then traffic routes to nginx service which, in its turn, routes it to Deployment/Pod.
In general topic about Kubernetes networking “under the hood” is very broad, deep and sophisticated.
If you need just nginx perhaps it is easier to use Helm tool.