TCP packets don't flow from external hosts to WinVista clients behind nat

Hello... I've got a strange trouble... FreeBSD 6.2 amd64 as nat-router: rl0 85.249.249.249 - ISP fxp0 10.0.0.1 - My Internat Net natd/ng_nat ipfw: allow all from any to any WinXP client machines work fine behind nat, but WinVista, FreeBSD (5.5/6.2) clients don't. It's very strange but it's

Re: TCP packets don't flow from external hosts to WinVista clients behind

Could be TCP window scaling. See http://en.wikipedia.org/wiki/TCP_window_scale_option Or the plain old PMTUD problem described in http://www.cisco.com/en/US/tech/tk870/tk877/tk880/technologies_tech_note09186a008011a218.shtml#backinfo =Adriaan= Nothing helps. I've tried to change client's