国外有同样问题的出现者，但无给出具体解决方法，我认为与兼容性有关。
Shark@Lau /home/dummynet/ipfw3-2012/binary
$ ./ipfw.exe -h
0 [main] ipfw 15148 find_fast_cwd: WARNING: Couldn’t compute FAST_CWD poin ter. Please report this problem to
the public mailing list cygwin@cygwin.com
ipfw syntax summary (but please do read the ipfw(8) manpage):
ipfw [-abcdefhnNqStTv] <command>
where <command> is one of the following:
add [num] [set N] [prob x] RULE-BODY
{pipe|queue} N config PIPE-BODY
[pipe|queue] {zero|delete|show} [N{,N}]
nat N config {ip IPADDR|if IFNAME|log|deny_in|same_ports|unreg_only|reset|
reverse|proxy_only|redirect_addr linkspec|
redirect_port linkspec|redirect_proto linkspec}
set [disable N…