> 1) should TCP check the sequence number to avoid RST bombs? > > Not only should but must, and I think does; see RFC 793. It may be that most TCP's check sequence number of RST's. I thought I'd add, though, that there are plenty of TCP implementations which don't bother to put the correct sequence number into RST's they generate. I know this because I do a lot of TCP connection analysis by tracing SYN/FIN/RST packets, and I have to special-case the RST packets in my scripts because their sequence numbers are often bogus. Vern