Newbie question: is net.inet.ip.fastforwarding intended for routers only?

[Xin LI]

As title. To my imagination (I have taken a sight on the kernel networking
code), the fastforwarding path is intended for routers only, so if I want
some functionalities, for example, NAT, the fastforwarding is not useful,
and my experiment shows that if I enable it, ipfilter's NAT will be broken.
Am I right?

Thanks in advance!

Xin LI