NAT rules vs firewall rules

[cesjr]

Hi guys ,  NAT perform port address translation(PAT)  from LAN IP to WAN IP , but if I setting firewall rules on WAN direction (usually deny all ).  How should firewall knows to bypass WAN rules and send back to my client  ?

I know there is a NAT mapping table , but the port number EX:12789 was blocked on WAN Rules .

Is it different between firewall rules and NAT rules ?

[johnpoz]

When you create a port forward, the default setting is to auto create the firewall rule on wan for you to allow..

If you have rules ahead that specific block other than the default deny then that could fail - and you would have move the wan allow for your nat to be above any explicit blocks of the ports your wanting to forward inbound.