What's the purpose of having port range for the 'forward-to-ports' when using Port Forwarding feature?

[Rufe Glick]

Hello,

On the 'forwarder' machine with ip address of 10.0.0.1 I set up port forwarding
using firewalld from of5001-5002/tcp range to ports 6001-6002 of 10.0.0.2 machine. Now
when I connect to 10.0.0.1 from a third machine to ports 5001 or 5002 both connections go
to port 6001 of the 10.0.0.2 machine; no connection ever goes to port 6002. So what's
the purpose of having range if connections to all 'forward-from-ports' always go
to the first port from the 'forward-to-ports' range? What am I missing?

Thank you,
Rufe