How to forward a port through OS balancer?

Question

Debian

Greetings, Habrauser!
There are 4 servers with virtual machines in the data center, we have 29 IP addresses for our services. Everything is also tied to the internal subgrid.
And so, actually, a question. IPs are running out, and the number of projects is growing. I tried to solve the issue with a balancer, but I can't access, for example, a database remotely. How can I do port forwarding through the same balancer (Debian)?
Thanks in advance.
PS I understand that it is possible through iptables, but I did not find ready-made solutions.

Answer 1

https://debian.pro/523 is the easiest way.
But for real-time traffic, it is better not to use this under high load.
Through the balancer, if you have haproxy, you can simply create VS-ki with one backend.