Problem with softflowd capturing packets while using IPFW

[Michael Jung]

Softflowd v0.9.8 / FreeBSD 10.3-RELEASE-p7

I have used softflowd for years to build netflow packets without issue
until now. I have never tried to use it while running IPFW.

When running softflowd while IPFW is running using the source interface
for NAT it does not build flows.  I can confirm IPFW is the issue as
it work without issue when IPFW is not loaded.

softflowd emits no errors even in debug mode.

tcpdump on the same source interface has no problems capturing packets.



I also tried creating a netgraph  bridge from the source NAT interface

kldload ng_ether
kldload ng_bridge
kldload ng_eiface

# create and connect bridge to PHY

ngctl mkpeer em0: bridge lower link0
ngctl connect em0: re0:lower upper link1

# name the bridge

ngctl name em0:lower em0br0

# Connect first virtual NIC

ngctl mkpeer em0:lower eiface link2 ether

But the only thing I see on the bridged interface is broadcast traffic
when on other boxes without IPFW I would see all bridged traffic which 
is
odd.


Is there some magic I need in my IPFW rules or is another approach 
needed?

Thanks in advance.

--mikej