I have a local cluster and an external client on the internet. The solution is communicating on several ports, but though a HAproxy upstream LB. The cluster handles many other solutions on the local network.
In this case, the cluster sends its local IPs back to HAproxy and further to the client on the internet. The communication stops, because the client can't find the "local servers". Is there a way, the HAproxy can rewrite a local IP to a well defined external IP? In the end, it's all about port numbers.