sequence numbers in TCP RST's (was Re: Watcher page moved)

[vern () ee lbl gov (Vern Paxson)]

>        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