Significantly slow IPFW + NATD + amd64-bit FreeBSD 9 (CURRENT)

In this part:

Current (testing) 64-bit FreeBSD + IPFW+ NAT decreasing NIC speed.

ADVICE: TRY "PF firewall"

I tried setup NAT with IPFW, compiled new kernel and then I found that there is very slow connection.

amd64-bit + NAT + IPFW copying  very slow

After I disabled NAT and IPFW then speed was increased.

64-bit FreeBSD 9-CURRENT :
With IPFW: 1.2 MB/sec
Without IPFW: 31 MB/sec

Writing to samba server

IPFW+NAT run with i386 (stable version) without speed decreasing.
I like IPFW and DUMMYNET for its relatively easy bandwidth shaping.

For now I'm not alone facing the same issue.

references here

PS: Hackers advices:
- mpd (and PF)
- in-kernel NAT
- See the 'NETWORK ADDRES TRANSLATION' section in the ipfw manual

For now I need a bit more testing machines.