Hi, Sorry for having posted this message twice. I did't see it coming back through the list, and realized I sent it from the wrong address. I then sent it again from the address whic is actually subscribed. Now that I wondered why even the second mail didn't come back to me, I looked in the list archive and saw that the mail actually came through the list, even twice. I wonder why I didn't get a copy, because all other lists I know send copies of mails also to the sender himself - is the netfilter list different in this? But for the topic itself: unfortunately, I got no reply at all, I assume because you are annoxed by the double post, or because the question was unclear. As I explained the first problem, I try to ask the question in a different way: When tyring to set up the rule: iptables -A INPUT --protocol tcp --tcp-flags ALL SYN,ACK -j DROP I only get the error: iptables: No chain/target/match by that name When I remove the tcp-flags part, the rules is accepted. I assume to be missing a kernel module for tcp-flags match, but have no idea which module this could be. Which Kernel module is required for getting tcp-flags matches? Henning