ipfw fwd to closed port

[Kristof Provost]

On 2016-06-09 02:02:40 (+0300), Slawa Olhovchenkov <slw at zxy.spb.ru> wrote:
> Forwarding by ipfw to closed local port generating RST packet with
> incorrect checksun. Is this know ussuse? Need open PR?

Where did you capture the packet? If you've captured the packet on the
machine that generated it tcpdump may indeed claim that the checksum is
wrong, because it's computed by the hardware (so after tcpdump captured
it).

Regards,
Kristof