I have some question about the description of IPFW in the handbook...

[Cyberman Wu]

In 28.6.1 it says only adding firewall_enable="YES" in rc.conf will enable
IPFW, and the message will showed:
ipfw2 initialized, divert disabled, rule-based forwarding disabled, default
to deny, logging disabled

And when I did that I got some info like that:
ipfw2 (+ipv6) initialized, divert loadable, rule-based forwarding disabled,
default to deny, logging disabled

Only divert is different.

But when I try to use ipfw I got a error, just like the same before I
enable it in rc.conf:
ipfw: getsockopt(IP_FW_GET): Protocol not available

Before that I've tried to build a new kernel with 'options IPFIREWALL'
and it seemed can work:
after the new system booted all the network blocked, then I see the
way said in the handbook
and tried it.

I'v tried to search on the FreeBSD web site but got nothing about
that, and through google
the other sites only say I should recompile the kernel.

I'm a new user for FreeBSD, before that I've only used Fedora, and
many years ago, Redhat.
This time our web server running Win2003 got some problem and I'm
trying to shift it to FreeBSD.
Is there any good articles describing how to builder a reliable and
efficient web server?