I want to develop a firewall at other platform, and do NAT(SNAT and DNAT) and Filter at PRE_ROUTING(for example: ip_rcv()). Is it OK? If yes, I need note which problems? _________________________________________________________ Do You Yahoo!? 雅虎通网络KTV, 随时随地免费卡拉OK~~ http://rd.yahoo.com/mail_cn/tag/?http://cn.messenger.yahoo.com//chat/index.html