Normal (full cone) NAT

[rainette]

Hi,

i'm working on some hole punching and i've just discovered that opnsense is doing symmetric NAT.
I would like to change my NAT to full cone (normal) or restricted.

What's my option here to do so ? I didn't find anything useful in the NAT section of opnsense (or pfsense). It looks like openBSD and freeBSD do symmetric NAT by default. How to change that ?

Thank you