[rocky] question about router to double IPs

Hello

I have a rocky OS with two public IPs, saying they are:

eth0: 1.1.1.1 eth1: 2.2.2.2 default gw: 1.1.1.254

The problem is, when the external user access the IP of eth1 (2.2.2.2), the returned package is routed out by default gw, and the source IP in returned package would be 1.1.1.1, rather than the expected 2.2.2.2

The path looks like: (external user) -> 2.2.2.2 -> 1.1.1.1 -> 1.1.1.254 -> (external user)

In this case the external user was seeing the source IP in the returned package is 1.1.1.1, which is not correct IMO. How can I resolve this issue?

Thank you.