Instance IP Address is dynamic IP address.
When an instance needs to be rebooted for some reasons, its port are change. Can not always use the same port.
but, Endpoint URL is always the same.
Always-on connection it is supposed to be through the Endpoint.
Endpoint URL is mapped to the first port only.
port#1: 3456 <= mapped to Endpoint
Endpoint need all port opened after endpoint enabled.
EndPoint URL is HTTP backend support. (TCP/UDP not suppoted.)
This is intended to be used in a web server and API Server.
Entity of Endpoint is a load balancer. This will load balance the communication of multiple back-end instance automatically.
All of the instances automatically get rebooted almost every week, The average life span of the ip address and port is one week. Sometimes it changes in one day.