Need help, some thing goes with wrong with Bridge-networking

[steven]

Dear Sir:
        Those days i tried build an in-line firewall, I take freebsd
as a good operation system because it is safety and stabilty, but i
came with trouble when i follow the handbook to bridge the two
Ethernet Card, the
book(http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/network-bridging.html)
says that i should recomplie the kernel to add options BRIDGE
into it, however, after  compiling the new kernel, typing comamds
including "sysctl -w net.link.ether.bridge.enable=1","sysctl -w
net.link.ether.bridge.config=rl0,rl1", the bridge seems out of
working, and my fressbsd system version is 6.1, those two network card
is not assign any static ipv4 address, Can you tell me why it comes
intn that, dieing to hrear from  your answer, and i'm appriciate for
it.


             yours steven