Have you had a read of this page https://docs.vmware.com/en/VMware-NSX-T-Data-Center/3.2/administration/GUID-46900DFB-58EE-4E84-9873-... ?
It is essentially stateless Nat and can be configured when you have an active active gateway. This can't be done with traditional Nat as that is stateful and requires a gateway to be in active standby, which allows the states / tables to be maintained.
Hopefully this clears it up for you.
First of all, thank you for your assistance.😊
Yes, I have read that document but I don't get how asymmetrical will occur?
So to sum up Reflexive NAT from my understanding, it is 1-to-1 mapping unlike SNAT and DNAT where you can have one-to-many relationship, right?
Some 'deeper' info for you here http://linux-ip.net/html/nat-stateless.html.