double IP address on SPS nodes

In order to manage SPP initiated and SPS initiated we configured a new connection policy for ssh and rdp. The default connection policy to use classic SPP initiated and the second connection policy for using sps initiated. The advice is to set a different port from the original (22 or 3389) to avoid conflict problems. The customer is not in favour of opening a port other than 22 or 3389 and we wanted to propose an alternative solution. We thought of setting a second IP address on the network cards of the two SPS nodes but received an error.

I can't attach any screenshot but the error is:

Invalid configuration

nnx.validator.SemanticError.: IP addresses are set in the same network between multiple interface 

and so on

Is it possible to set a second IP address on the SPS card? always in eth0 or eth1? So, the second IP would be used in the connection policy for the sps initiated (in the To field).

(the port is 22 for both, the connection policy dedicated to the spp initiated and the second connection policy dedicated to sps initiated with the same port but different IP address just to differentiate the rule used for sps initiated).

can it work? how should we configure this second IP to be assigned to the sps node?

thank you for your help!